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Overview of a Thin Film ResistorThin film resistors utilize a very thin resistive layer deposited on top of a ceramic substrate. The defining characteristic that separates thin film from thick film is the thickness of this resistive layer, which is typically around 0.1 microns (1000 Angstroms).In contrast, thick film resistors have a layer thickness that can be up to 1000 times greater (typically ranging from 10 to 100 microns). While thickness is the primary categorical difference, the two types possess distinct physical characteristics and utilize completely different fabrication techniques. Thin film resistors are the standard for high-precision technologies because they offer superior accuracy, tighter tolerances, and better stability. However, this precision comes with a higher manufacturing cost compared to their thick film counterparts.Structure of a Thin Film ResistorOverview of a Thick Film ResistorThick film resistor definition: This type of resistor is characterized by a resistive paste covering a ceramic base. While they may look identical to thin film resistors on the outside (especially in SMD chip format), they are manufactured using a screen-printing technique rather than vacuum deposition. Physically, the resistive element is significantly more robust in terms of mass, being roughly 1000 times thicker than thin film layers.Structure of a Thick Film ResistorVideo: Thin Film vs. Thick Film ResistorsVideo Description: This video primarily discusses the key differences between thin film and thick film resistors, including construction methods and performance metrics. For detailed technical data, please refer to the article below.Construction of a Thin Film ResistorThin film resistors are created through a process called vacuum sputtering (physical vapor deposition). The resistive material is sputtered onto a high-purity ceramic substrate. Following deposition, the surface is processed using ultraviolet radiation and etching techniques to create the initial resistive pattern.Common materials used include Tantalum Nitride (TaN), Nickel-Chromium (Nichrome or NiCr), and Ruthenium Oxide. Once the film is etched, the precise resistance value is achieved via laser trimming, which cuts into the film to lengthen the resistive path.Construction process of a Thin Film ResistorThe final resistance depends on the film's thickness and the laser-trimmed pattern. While axial lead versions (often called "Metal Film Resistors") deposit the film on a cylindrical core, the surface mount (SMD) versions deposit it on a flat ceramic chip. The thin film structure results in very low parasitic inductance and capacitance, making them ideal for high-frequency applications.Construction of a Thick Film ResistorA thick film resistor is produced by screen-printing (silk-screening) a conductive paste onto an insulating substrate. This paste is then fired at high temperatures to form a permanent bond. The paste consists of a mixture of a binder (glass frit), a carrier (organic solvent), and the active resistive element (metal oxides).The resistive paste is applied over a ceramic base (typically 95% Alumina), which also contains glass frit and binders to hold the structure together during the firing process.Construction process of a Thick Film ResistorThese resistors are mass-produced in massive quantities, making them extremely affordable. This is crucial for consumer electronics; by printing resistors directly onto substrates (in hybrid circuits) or using cheap SMD chips, costs are minimized. Thick film resistors can tolerate high temperatures (up to 155°C-300°C depending on the series) and are non-magnetic, making them suitable for MRI and CT scanners. Unlike thin film, thick film resistors generally have higher voltage coefficients and noise levels, but they offer excellent surge handling capability due to the larger mass of the resistive element.Thin Film Resistor Fabrication DetailsResearch into Ti/TiN (Titanium/Titanium Nitride) thin-film resistors has shown remarkable thermal stability. Electrical studies indicate the "Ti" layer has lower resistance than the TiN layer. Failures in these specific films are often analyzed using Joule heating mechanisms.Activation energies for failure have been observed at 1.3 eV (Ti layer) and 1.8 eV (TiN layer). Based on these findings, certain high-reliability Ti/TiN resistors can remain electrically stable for over 10 years if maintained below 311°C.In silicon microelectronics, films like Titanium and Tantalum Nitride serve dual purposes: as resistors and as diffusion barriers or adhesion layers. They are critical in the fabrication of MMICs (Monolithic Microwave Integrated Circuits) and RFICs due to their stable TCR (Temperature Coefficient of Resistance) and specific resistivity.Thick Film Resistor Fabrication DetailsThick film components are created by screening "pastes" onto hard substrates, usually 95% Alumina (Al2O3). This substrate is slightly less pure than the 99.6% Alumina often used for thin-film applications to ensure better adhesion of the glass frit.The firing temperature is typically around 850°C. The resistive material is usually a Ruthenium Oxide (RuO2), Iridium, or Rhenium Oxide based "cermet" (Ceramic-Metallic), NOT carbon. While the resistor body is often black, this is due to the protective epoxy encapsulation, not carbon content. A laser trim is applied to adjust the value, and a final protective glass or epoxy layer is added.Thick film is an additive process, whereas thin film is often subtractive (etching). Because the process is lower-tech (screen printing vs. vacuum chamber) and materials are less costly, thick film resistors are the standard "commodity" resistor found in almost all general-purpose electronics.Thin Film vs. Thick Film TechnologyThin Film TechnologyVacuum deposition sputters the resistive layer (usually Nichrome or Tantalum Nitride) onto the substrate. This produces a uniform metallic layer ~0.1 µm thick. Photolithography and etching are used to pattern the film, followed by laser trimming for calibration.Thin film is the choice for precision. They feature tight tolerances (down to 0.01%), low Temperature Coefficients (TCR as low as ±2 to ±5 ppm/°C), and very low current noise. They excel in high-frequency applications due to low parasitic inductance. Common uses include medical devices, precision audio, test instrumentation, and automotive engine control units.Thin Film Resistor SchematicThick Film TechnologyGaining popularity in the 1970s, thick film is now the most dominant resistor technology globally. It is the most cost-effective solution, utilizing a paste of metal oxides (Ruthenium), glass frit, and organic carriers. After printing and firing at 850°C, the layer becomes a glass-like cermet, naturally resistant to moisture.Typical characteristics include a TCR of 100 to 200 ppm/°C and tolerances of 1% to 5% (though 0.5% is available). While less precise, thick film resistors can handle higher power per unit area and significantly higher surge currents than thin film. They are found in virtually every consumer device with a battery or plug.Thick Film Resistor SchematicTypical Firing Profile for Thick Film PasteComparison of Properties: Thin Film vs. Thick FilmCharacteristicThin FilmThick FilmFilm Thickness~0.1 µm~10 to 100 µmManufacturing ProcessSputtering (Vacuum Deposition)Screen and stencil printingResistive MaterialUniform metallic film (Nichrome, TaN)Paste of Ruthenium Oxide / Glass fritTolerance±0.01% to ±1%±1% to ±5% (Standard)0.5% (High End)TCR (ppm/°C)±5 to ±50±50 to ±200Noise (dB)Low (< -30 dB)Higher (Can be +20 dB)High FrequencyExcellent (Low inductance)Good, but higher capacitanceSurge/Pulse CapabilityLower (Low mass)Higher (High mass)CostModerate to HighLowAdvantages: Thin Film vs. Thick FilmThin Film AdvantagesThick Film AdvantagesExtremely low Temperature Coefficient (TCR)Very low cost (Economical in bulk)High precision (tight tolerances)High resistance values available (up to 10 Tera Ohms)Low current noise (ideal for Audio/Amp)Robust against high voltage and surge pulsesLow parasitic inductance/capacitance (RF use)Excellent reliability in harsh environmentsHigh stability over timeAvailable in massive quantities and sizesDisadvantages: Thin Film vs. Thick FilmThin Film DisadvantagesThick Film DisadvantagesHigher manufacturing costHigher noise levelsLower power rating for the same sizeWorse temperature stability (High TCR)Susceptible to electrostatic discharge (ESD)Lower precision (typically 1% or 5%)Delicate (lower mass for absorbing heat surges)Mechanical stress can shift resistance valuesApplications ComparisonRule of Thumb: If your circuit requires 1% tolerance or looser, and standard temperature stability is acceptable, choose Thick Film for cost savings. If you need 0.1% tolerance, high frequency, or minimal drift over temperature, choose Thin Film.Thin Film ApplicationsThick Film ApplicationsPrecision: Medical Instrumentation, Aerospace, Test & Measurement EquipmentGeneral Purpose: Pull-up/Pull-down resistors in digital logicAudio: High-end audio amplifiers (low noise required)Consumer: PCs, Laptops, Televisions, Power AdaptersRF/Communication: Telecommunications, GPS, RadarAutomotive: General cabin electronics, lighting controlPower: Precision voltage references, Feedback loops in high-end power suppliesPower: Snubber circuits, generic voltage dividersWirewound Precision Resistors vs. Thin FilmWhile wirewound resistors offer the ultimate precision and stability (often better than thin film), they are bulky and inductive. Thin film bridges the gap: it is far more precise than thick film, but maintains the small form factor and high-frequency capability that wirewound resistors lack.If the application requires fast rise times (microseconds) or high frequencies (megahertz), thin film is superior to wirewound. If cost is the only driver, thick film is used. If size and high frequency are critical, thin film is the winner.Properties: Wirewound vs. Thin Film ResistorsFAQ: Thin Film vs. Thick Film ResistorsWhat is the main difference between thin and thick film resistors?The main difference is the manufacturing process and layer thickness. Thin film uses vacuum deposition (sputtering) to create a ~0.1 µm layer, resulting in high precision. Thick film uses screen printing to create a ~100 µm layer, resulting in a robust, low-cost component.Why are thin films considered "better" than thick films?"Better" depends on the metric. Thin films are better for performance: they have tighter tolerances, lower noise, and better temperature stability. However, thick films are "better" for cost and surge handling.Can I replace a thick film resistor with a thin film resistor?Generally, yes. A thin film resistor will provide better performance (lower noise, better stability) than the thick film resistor it replaces. However, check the pulse/surge rating; if the thick film resistor was chosen specifically to absorb high energy pulses, a standard thin film resistor might fail.What is the failure mode of these resistors?Thick film resistors can drift in value over time or crack under thermal stress. Thin film resistors are susceptible to electrolytic corrosion if moisture penetrates the coating, or ESD damage due to the thinness of the conductive layer. strong { font-weight: 700; color: #222; } .caption { text-align: center; font-style: italic; color: #3598db; font-size: 14px; margin-top: -10px; margin-bottom: 30px; } table { width: 100%; border-collapse: collapse; margin: 20px 0; font-size: 15px; box-shadow: 0 2px 10px rgba(0,0,0,0.05); } th, td { padding: 12px 15px; border: 1px solid #ddd; text-align: left; } th { background-color: #3598db; color: white; font-weight: bold; } tr:nth-child(even) { background-color: #f8f9fa; } tr:hover { background-color: #eef7fc; } .highlight { background-color: #e8f4fd; padding: 15px; border-left: 4px solid #3598db; margin: 20px 0; }

Overview of switchesMain parameter of switchesSwitch SymbolSwitch DiagramWhat is a toggle switch?How does toggle switches work?Video related to toggle switchesFive ways toggle switch wiringCircuit diagram of toggle switchTypes of Toggle SwitchDPDT Toggle SwitchDPST Toggle SwitchSPDT Toggle SwitchSPST Toggle SwitchLED Toggle SwitchAdvantages and Disadvantages of toggle switchesRocker Switches vs Toggle SwitchesToggle Switch ApplicationsToggle Switch FAQ  Overview of switchesA switch is a piece of equipment used to stop current flow in a circuit. Simply put, a switch has the power to complete or disrupt an electrical circuit. To turn a device ON and OFF, every electrical and electronic application makes use of at least one switch.Switches are therefore a component of the control system, and control action is impossible without them. A switch has two possible states: completely ON (by shutting its contacts) and completely OFF (by opening its contacts).A switch establishes a closed conduit for the current to flow when its contacts are closed, which causes the load to draw power from the source. As demonstrated in the figure below, no power is used by the load when a switch's contacts are open. Main parameter of switchesSwitches ParametersVoltage ratingThe insulation materials, contact separation, rate of separation, and general safety considerations are some of the variables that affect voltage rating.Current carrying ratingThe electronics switches' current specifications are crucial since they will only be able to transport a particular amount of current through their contacts.Current switching ratingAn electromechanical switch's current switching rating is typically lower than its current carrying rating. The problem is that forming and breaking contacts creates arcing, and the contacts can only handle so much of it before the wear on the contacts significantly limits the operational life.Switch formatFor every electronics circuit design, choosing the appropriate switch format is essential. Toggle switches, slider switches, rotary switches, DIPs, thumbwheels, and many more are among the many various switch formats. Any switch's selection process includes the format.Number of operationsThere is always a tiny degree of wear as the contacts of a switch move across one another to ensure the best resistance is obtained.Contact resistanceThere is a higher contact resistance than there would be if the conductor were continuous because a switch's contacts are not a continuous conductor but can be broken and rebuilt.Power ratingThe maximum power that the switch can manage while working is indicated by its power rating. Overriding this rating may result in an excessive buildup of heat inside the device, which could lead to the switch failing and create a safety issue.Inductive ratingIf not handled properly, any inductance in a circuit will raise the intensity of arcing at the contacts and shorten the life of the switch. This means that once current is flowing, it is challenging to stop since the inductance will produce significant back EMFs when the current is stopped. This is because any inductance in the circuit will oppose the change taking place.Contact typeThere are two different types of contacts used in change-over type electromechanical: Break before make and Make before break.  Switch SymbolSwitch Symbol Switch DiagramSwitch Diagram What is a toggle switch?Toggle switches are electrical switches that be opened or closed using a lever or handle that is moved forward and backward. Toggle power switches and joystick switches are other names for these switches. These switches can be used in any electrical application because they are flexible devices.Since switches are typically manipulated manually, the toggle switch, which functions as a straightforward ON/OFF switch in many electrical circuits, is essential. The toggle switch controls the flow of current from the power source to a device or within a device by use of a lever.Toggle Switch How does toggle switches work?The armature switches the contact into position to start or halt an electrical flow when the switch operator pulls the toggle (the actuator). To put it simply, pushing the toggle can turn a gadget on or off. There are two functions that can be used; a momentary function means that the switch is only engaged when the force is applied. An internal spring mechanism forces the armature to return to its initial position in order to accomplish this. A latching toggle switch, in contrast, keeps the state after being depressed until the toggle is depressed once again to release the switch.The basic toggle switch design is as follows, although being available in various forms and configurations. When the toggle is pulled, an armature (a component conducting electrical current) attached to it moves, adding or removing an electrical contact from a circuit and activating or deactivating the circuit.Even though momentary switches also have an associated spring that will draw the actuator back to its starting point if released, the switch will typically stay in place unless manually pushed again. Video related to toggle switchesVideo Description: Add a switch easily to any household electronics item or automotive project easily by watching this short video. Five ways toggle switch wiringStep One: Look at the instruction about the toggle switchesElectrical setups for the many types of equipment that you might wish to install toggle switches on vary substantially. As a result, no single guide is likely to offer a universally applicable solution. The procedures in this section are intended to serve as general guidance for a straightforward on-off (also known as SPST) toggle switch. They should never take precedence over any installation instructions that came with your toggle switch or the appliance you're placing it into.You can look at the below instruction about the toggle switches:Toggle Switches Instruction Step Two: Your device's supply wire should be cutYou must link your toggle switch to the device's power source in order for it to act as an on-off switch. Cut the supply wire for your device with wire cutters at a spot that will make it easiest to route one or both ends of the cable to the switch. Using a wire stripper, remove about 12 inch (1.3 cm) of insulation from each end of the wire.Cut the supply wire Step Three: If the cable does not reach the switch from either end, add a pigtail.A pigtail is a brief wire piece with both ends stripped, often measuring under 6 inches (15 cm). It can be used as a form of "extender" by being attached to cables that aren't quite long enough to reach your toggle switch.Pigtail connetced to switches Step Four: Connect the supply wire to the toggle switchNow that the device's supply wire has been severed, you must insert your toggle switch so that it can control the circuit's current flow in the middle of the break. The kind of toggle switch you have will determine how you should proceed. Step Five: Test your switchWhen your toggle switch is properly wired, carefully reattach the power to the device and check the toggle switch's operation. You can swap out the panel or housing if everything functions as it should. Congratulations! A toggle switch has been fitted successfully. Circuit diagram of toggle switchThe SPDT toggle switch's circuit schematic is displayed below. A 6V battery, two resistors R1 & R3, two LEDs D1 & D3, and a 21236N switch can be used to construct this circuit.Three terminals, including one input and two outputs, make up this switch. Thus, we can acquire two outputs, the first of which comes from pins 2 (COM) and 1 and the second of which comes from pins COM and 3. In three-way circuits, this switch is mostly used to control electrical appliances from two places.The pins 1 and 3 are connected to D1 (an LED) and D2 (an LED), respectively, in the circuit shown above. When pin 1 is toggled, the D1 LED turns on and the D2 LED turns off. In a same manner, when pin 3 is toggled, D2 LED will turn ON and D1 LED will turn OFF. Consequently, we are able to manage two loads using a single SPDT toggle switch.Toggle Switch Circuit Diagram Types of Toggle SwitchThere are four main versions of these switch designs, each of which has a different combination of throws and poles, such as SPDT, SPST, DPDT, and DPST. Poles of these switches are often the distinct power supply controlled by each switch, whereas throws are the various areas the switch can be used, such as ON & OFF.DPDT Toggle SwitchDPST Toggle SwitchSPDT Toggle SwitchSPST Toggle SwitchLED Toggle Switch DPDT Toggle SwitchDouble pole, double throw (DPDT) toggle switches are used to establish or terminate connections between two conductors and two different circuits. There are six terminals on these switches, and terminals 3 and 4 get the necessary power to drive the loads on the other terminals, which are 1, 5, 2, and 6. Four-way or four-position switches are the names given to these switches.DPDT Switches The six terminals of a DPDT toggle switch are. The toggle switch is represented by terminals 3 and 4. The electricity required to drive the loads on terminals 1 and 5, as well as 2 and 6, is supplied to these terminals. Between terminals 1 and 5, terminal 3 can switch. Therefore, terminal 3, which represents the toggle switch, can switch between operating the fan and operating the motor if a fan is connected to terminal 1 and a motor is connected to terminal 5. The same is true for terminal 4, too. Between terminals 2 and 6, terminal 4 can switch. In this case, terminal 4, which acts as the toggle switch, can switch between the heater and the blower if a heater is connected to terminal 2 and a blower is connected to terminal 6.Two input switches on a DPDT switch can each be connected to one of two terminals. It can therefore use two switches to control four distinct circuits or devices.The circuit for a DPDT toggle switch is illustrated below:DPDT Toggle Switch Circuit Diagram  DPST Toggle SwitchThe name "DPST" refers to a double-pile single throw switch, which is used to establish or terminate the connection between two circuit conductors inside a single branch circuit. These switches typically have four terminals that can be used to simultaneously connect and disconnect two pairs of terminals.DPST Switches A 30A DPST switch is used in this wiring layout to connect a 240V AC load appliance (such as a dryer or water heater). The hot wires for 240V are immediately linked to the two pole, single throw switch and the load point as it is illustrated because there is no need to wire the neutral wire. The dryer is directly linked to the ground wire. When turned OFF, the DPST switch will cut both hot wires. Similar to that, while in the ON position, it will join both Hot wires.DPST Toggle Switch Circuit Diagram SPDT Toggle SwitchA single conductor connection with any of two additional single conductors can be made or broken using a toggle switch known as an SPDT, or single pole, double throw. These switches typically have three terminals, which are typically utilized in pairs. Any load must be connected to the first terminal in order to power a specific gadget. To power the loads on Terminals 1 and 3, Terminal 2 receives the necessary power, while Terminal 3 is utilized to connect to any load and turn on any device. This switch can therefore power any of two circuits. Three-way switches are another name for these kinds of switches.SPDT Switches Three terminals make up an SPDT toggle switch. Any load can be connected to Terminal 1 in order to power a specific appliance. Furthermore, any load can be connected to terminal 3 to power any device. The power required to power the loads on terminals 1 and 3 is delivered to terminal 2 at this point. A SPDT switch can therefore operate any of two circuits. It can switch between the two circuits so that various gadgets or circuits can be powered with just a flick of the switch. The circuit for an SPDT toggle switch is illustrated below:SPDT Toggle Switch Circuit DiagramWe link our 9-volt DC power source to terminal 2 in this circuit. The toggle switch at terminal 2 allows us to switch between terminals 1 and 3. A fan is attached to Terminal 1. The DC motor does not operate when the switch is flipped to the left (terminal 1). The DC motor turns on when the switch is flipped to the right (terminal 3), but the fan does not. You can see how we can control two distinct circuits or devices with an SPDT switch in this manner. A double throw switch offers two possibilities. SPST Toggle SwitchSPST, which stands for "Single Pole Single Throw," refers to a device with two terminals, such as input and output. These switches function just like an ON/OFF switch. This switch's primary job is to establish or terminate a connection between a single conductor and a single branch circuit. Once this switch is opened, the circuit will be cut off, stopping any current flow through the load. When the switch is closed, current flows through the load in a similar manner.SPST Switches A SPST toggle switch only has 2 terminals, as you can see. The input is on terminal 1. The output will be at the other terminal. Simple ON-OFF switches are what SPST toggle switches do. They interrupt the circuit when open, preventing current from reaching the load. Current can move across a closed circuit and drive the load. You can see that the DC motor may be started or stopped using this circuit simply as an ON/OFF switch. The circuit for an SPST toggle switch is illustrated below:SPST Toggle Switch Circuit Diagram LED Toggle SwitchToggle switches with illumination operate at 12 volts DC and light up to show the status of your circuit. Add some flair to your switch and control panels by using these lit toggle switches. Our assortment is completed by toggle switches with LED tips, duck bills, and longer handles. Red, blue, green, and amber are the available illumination colors. Toggle switches with illumination are available in an ON-OFF, single pole, single throw design. The switches' connections, which consist primarily of power in, power out, and a ground for the indicator light, are 1/4 inch push-on terminals. The fundamentals of how to wire an illuminated toggle switch are demonstrated in our video.You shouldn't have any trouble wiring an LED rocker switch if you pay close attention to where your ground, power, and acc pins are placed, follow the diagram below (which uses Oznium's LED Round Rocker Switch with a recommended mounting hole diameter of 3/4 inch) :LED Toggle Switch Circuit Diagram Advantages and Disadvantages of toggle switchesAdvantagesDisadvantagesUse of these switches with circuit boards is optimal.While using these switches, a clicking sound will be heard.These switches often have a small footprint, are incredibly sturdy, and are very easy to seal.When compared to rocker switches, these are bigger and bulkier.These switches are effective in controlling electricity.It requires a toggle lock washer.There are small and regular sizes of these switches available.Only low voltage circuits can use it.A lever can be used to extend and operate them.-These switches are energy efficient since they utilize less -These switches are very strong.- Rocker Switches vs Toggle SwitchesRocker switches and toggle switches are the two primary categories of maintained switches. The advantage of having a rocker switch is that you can typically add images, symbols, or even writing to the switch's face to make it more personalized. It therefore especially helpful in situations where function communication is required. Switches that can be sealed easily are perfect for usage with circuit boards. indicating increased resilience against water and dust. enhancing the switch's suitability for hostile conditions.Which switch is best for your project will ultimately depend on its design and environmental factors. From a design standpoint, some people favor the toggle switch's appearance, while others like the rocker switch's more common appearance. Your choice will be influenced by the circumstances. A toggle switch, for instance, may be preferable if the product is for the marine industry because of its IP rating. Toggle Switch ApplicationsThese switches give drivers of cars easy access to headlights, comparable controls, and indicator lights.Conveyor belts, residual current devices, and other industrial and electrical equipment employ these (RCDs).These switches are present in home, commercial, and industrial power outlets.It can serve as the primary switch for industrial machinery like conveyors and packaging machines as well as AC equipment.These switches are employed in switching headlights, logic-level programs, automobiles, and aviation control panels, among other things.Toggle switches are utilized as switching circuits in communications, commercial, and industrial equipment.  Toggle Switch FAQOverview and Applications of toggle switchAn electronic on/off switch is a toggle switch. The best purpose for toggle switches is to change the status of system settings and functionalities. To allow users to select between two opposed states, toggles may be used in place of two radio buttons or a single checkbox. What are the 4 types of switches?Single pole single throw, single pole double throw, double pole single throw, and double pole double throw are the four primary categories of switches. The differences between toggle and switchSince they both manage states but not in the same way, we must first distinguish between a toggle button and a toggle switch: Toggle button: Represents an action that changes a state. Two (or more) mutually incompatible states or possibilities that can be switched are represented by a toggle switch. Should a toggle switch be on the positive or negative?Never switch the ground return side; always switch the supply side. You can flip both lines if you're using a twin pole switch, but you must keep the ground line to the chassis intact. More corrosion is likely to occur on the negative terminal. What is a toggle switch?In order to switch an electrical circuit, toggle switches include an operating lever that can be moved up and down or left and right. A "toggle" is a little wooden rod that is used in place of buttons to fasten garments.

CatalogⅠ What Is a Thyristor？Ⅱ How Does a Thyristor Work?Ⅲ Thyristor I-V Characteristics Curves3.1 Thyristor turn-on3.2 Thyristor turn-offⅣ Thyristor Phase ControlⅤ Applications of ThyristorsⅥ Different Types of Thyristors and Their Uses6.1 Thyristors with turn-on capability (Unidirectional control)6.2 Thyristors with turn-off capability (Unidirectional control)6.3 Bidirectional controlⅦ Thyristor VS TransistorsⅧ ConclusionⅨ Frequently Asked Questions about Thyristor Ⅰ What Is a Thyristor？A thyristor is a four-layer solid-state semiconductor device having alternating P- and N-type materials. It only functions as a bistable switch, conducting when the Gate gets a current trigger and continuing to conduct until the voltage across the device is reversed biased or removed (by some other means). There are two designs, which differ in what causes the conducting state to occur. A modest current on the Gate lead of a three-lead thyristor regulates the larger current of the Anode to Cathode circuit. Conduction begins in a two-lead thyristor when the potential difference between the Anode and Cathode is sufficiently large (breakdown voltage). this video shows what a thyristor is  The first thyristor devices were commercially available in 1956. Because thyristors can handle a relatively significant quantity of power and voltage with a compact device, they have a wide range of applications in power control, from light dimmers and electric motor speed control to high-voltage direct-current power transmission. Thyristors can be found in power-switching circuits, relay-replacement circuits, inverter circuits, oscillator circuits, level-detector circuits, chopper circuits, light-dimming circuits, low-cost timer circuits, logic circuits, speed-control circuits, phase-control circuits, and many other applications. Originally, thyristors could only be turned off by reversing the current, making them impractical to use for direct current; later device types can be turned on and off via the control gate signal. The latter is referred to as a gate turn-off thyristor (GTO thyristor). Thyristors, unlike transistors, have a two-valued switching characteristic, which means that they can only be fully on or off, whereas transistors can be in between on and off states. As a result, a thyristor is ineffective as an analog amplifier but beneficial as a switch. Ⅱ How Does a Thyristor Work?A P-N-P-N-P-N thyristor has three junctions: PN, NP, and PN. If the cathode is a positive terminal, the outer junctions, PN and PN, are forward-biased, while the center NP junction is reverse-biased. As a result, the NP junction prevents positive current from flowing from anode to cathode. In a forward blocking state, the thyristor is said to be. Similarly, the outer PN junctions prevent the flow of a negative current. The thyristor is currently in reverse blocking mode. this video shows how a thyristor works A thyristor can also be in the forward conducting condition, which occurs when it gets a sufficient signal to turn on and begin conducting. Ⅲ Thyristor I-V Characteristics Curvesthyristor I-V characteristics curves3.1 Thyristor turn-onThe gate signal loses all control once the thyristor is turned "ON" and passing current in the forward direction (anode positive). This is due to the regenerative latching action of the two internal transistors. Any gate signals or pulses applied after regeneration has begun will have no effect because the thyristor is already conducting and fully-ON. The SCR, unlike the transistor, cannot be biased to remain in an active zone along a load line between its blocking and saturation states. Because conduction is controlled internally, the magnitude and duration of the gate "turn-on" pulse have no effect on the device's operation. Then, delivering a brief gate pulse to the device is enough to cause it to conduct, and it will remain permanently "ON" even if the gate signal is removed completely. As a result, the thyristor can be thought of as a Bistable Latch with two stable states: "OFF" or "ON." This is because, in the absence of a gate signal, a silicon controlled rectifier blocks current in both directions of an alternating current waveform, and once triggered into conduction, the regenerative latching mechanism means that it cannot be turned "OFF" simply by using its Gate. 3.2 Thyristor turn-offOnce the thyristor has self-latched into its "ON" state and is passing a current, it can only be turned "OFF" by either completely removing the supply voltage and thus the Anode (IA) current, or by reducing its Anode to Cathode current by some external means (the opening of a switch, for example) to below a value commonly known as the "minimum holding current," IH. The anode current must thus be lowered below this minimum holding level for the thyristors' internally latched pn-junctions to regain their blocking condition before a forward voltage is given to the device again without it instantly self-conducting. To conduct in the first place, a thyristor's anode current, which is also its load current, IL, must be greater than its holding current value. That would be IL > IH. Since the thyristor has the ability to turn "OFF" whenever the Anode current is reduced below this minimum holding value, it follows that when used on a sinusoidal AC supply, the SCR will automatically turn "OFF" at some value near the cross over point of each half cycle, and will remain "OFF" until the next Gate trigger pulse is applied. Because an alternating current sinusoidal voltage constantly switches polarity from positive to negative on every half-cycle, the thyristor can be turned "OFF" at the 180o zero point of the positive waveform. This effect is known as "natural commutation," and it is a crucial feature of the silicon controlled rectifier. Thyristors used in circuits fed by DC sources cannot have this natural commutation condition since the DC supply voltage is continuous, hence another mechanism to turn "OFF" the thyristor at the proper moment must be given because once triggered, it will stay conducting. Natural commutation, on the other hand, occurs every half cycle in AC sinusoidal circuits. The thyristor is thus forward biased (anode positive) during the positive half cycle of an AC sinusoidal waveform and can be triggered "ON" using a Gate signal or pulse. The Anode becomes negative throughout the negative half cycle, whereas the Cathode remains positive. This voltage reverse biases the thyristor, preventing it from conducting even while a Gate signal is present. So, by applying a Gate signal at the proper point during the positive half of an AC waveform, the thyristor can be triggered into conduction until the positive half cycle is completed. Thus, phase control (as it is known) may be used to trigger the thyristor at any position along the positive half of the AC waveform, and power control of AC systems is one of the numerous applications of a Silicon Controlled Rectifier, as shown. Ⅳ Thyristor Phase ControlThe SCR is "OFF" at the start of each positive half-cycle. When the gate pulse is applied, the SCR enters conduction and remains fully latched "ON" for the duration of the positive cycle. If the thyristor is triggered at the half-cycle start ( Θ= 0°), the load (a light) will be "ON" throughout the entire positive cycle of the AC waveform (half-wave rectified AC) at a high average voltage of 0.318 x Vp. Thyristor Phase Control The lamp is lighted for less time as the application of the gate trigger pulse increases along the half cycle ( Θ= 0° to 90°), and the average voltage given to the lamp is proportionally smaller, diminishing its brightness. A silicon controlled rectifier can thus be used as an AC light dimmer as well as in a range of other AC power applications such as AC motor-speed control, temperature control systems, and power regulator circuits, among others. So far, we've learned that a thyristor is simply a half-wave device that conducts only in the positive half of the cycle when the Anode is positive and inhibits current flow like a diode when the Anode is negative, regardless of the Gate signal. However, there are other semiconductor devices known as "Thyristors" that can conduct in both directions, are full-wave devices, or can be turned "OFF" by the Gate signal. To name a few, these devices include "Gate Turn-OFF Thyristors" (GTO), "Static Induction Thyristors" (SITH), "MOS Controlled Thyristors" (MCT), "Silicon Controlled Switch" (SCS), "Triode Thyristors" (TRIAC), and "Light Activated Thyristors" (LASCR), with all of these devices available in a variety of voltage. Ⅴ Applications of ThyristorsThyristors are primarily used to regulate high currents and voltages, and are frequently used to control alternating currents, where a change in polarity of the current causes the device to automatically turn off, a process known as "zero cross" operation. The device is considered to work synchronously because, once triggered, it conducts current in phase with the voltage provided across its cathode to anode junction with no further gate modulation necessary, i.e., the device is fully biased on. This is not to be confused with asymmetrical operation because the output is unidirectional, flowing exclusively from cathode to anode, and hence asymmetrical. Thyristors can be used to control phase angle triggered controllers, also known as phase fired controllers. They can also be found in digital circuit power supplies, where they act as a form of "improved circuit breaker" to prevent a power supply failure from damaging downstream components. A thyristor is used in conjunction with a Zener diode coupled to its gate, and if the power supply output voltage exceeds the Zener voltage, the thyristor will conduct and short-circuit the power supply output to ground (in general also tripping an upstream breaker or fuse). In the early 1970s, the first large-scale application of thyristors, with associated triggering diac, in consumer devices linked to stable power supplies within color television sets. The stable high voltage DC supply for the receiver was generated by changing the switching point of the thyristor device up and down the falling slope of the positive going half of the AC supply input (if the rising slope was used the output voltage would always rise towards the peak input voltage when the device was triggered and thus defeat the aim of regulation). The precise switching point was decided by the load on the DC output supply as well as AC input fluctuations. Thyristors have been utilized as light dimmers in television, film, and theater for decades, replacing inferior technology such as autotransformers and rheostats. They have also been utilized in photography as an important component of flashes (strobes). Ⅵ Different Types of Thyristors and Their UsesThyristors are classified based on their voltage and current characteristics, as well as their on/off behavior. 6.1 Thyristors with turn-on capability (Unidirectional control)1. Silicon controlled rectifier (SCR)SCRs are the most well-known type of thyristor. An SCR remains latched on even when the gate current is released, as indicated in the general thyristor description above. To unlatch, either the anode to cathode current must be removed or the anode must be reset to a negative voltage relative to the cathode. This property is ideal for phase control. When the anode current reaches zero, the SCR stops conducting and the reverse voltage is blocked. Switching circuits, DC motor drives, AC/DC static switches, and inverting circuits all require SCRs. 2. Reverse conducting thyristor (RCT)Thyristors often allow current solely in one direction while blocking current in the other. An RCT, on the other hand, is made up of an SCR integrated with a reverse diode, which avoids unwanted loop inductance and lowers reverse voltage transients. The RCT enables electric conduction in the opposite direction, resulting in enhanced commutation. RCTs are utilized in high-power choppers' inverters and DC drives. 3.Light-activated silicon-controlled rectifier (LASCR)These are also referred to as light-triggered thyristors (LTT). When light particles reach the reverse-biased junction of these devices, the number of electron-hole pairs in the thyristor increases. The thyristor will turn on if the intensity of the light exceeds a specific value. An LASCR provides total electrical isolation between the light source and the power converter's switching component. LASCRs are found in high-voltage direct current transmission equipment, reactive power compensators, and high-power pulse generators. 6.2 Thyristors with turn-off capability (Unidirectional control)When a sufficient gate pulse is supplied, traditional thyristors, such as SCRs, turn on. To turn them off, the main current must be cut. This is troublesome in DC to AC and DC to DC conversion circuits where current does not naturally zero out. 1. Gate turn-off thyristor (GTO)A GTO varies from a typical thyristor in that it can be turned off by applying a negative current (voltage) to the gate without requiring the current between the anode and cathode to be removed (forced commutation). This means that a gate signal with a negative polarity can turn off the GTO, making it a fully controlled switch. It is also known as a Gate-Controlled Switch, or GCS. A GTO's turn off time is approximately ten times faster than that of a similar SCR. Symmetric GTOs have reverse blocking abilities that are comparable to their forward voltage ratings. Asymmetric GTOs lack significant reverse voltage blocking capacity. Reverse conducting GTOs are made up of a GTO and an anti-parallel diode. Asymmetric GTOs are the most common type on the market. 2.MOS turn–off thyristor (MTO)An MTO is a combination of a GTO and a MOSFET that improves the turn-off capability of the GTO. GTOs require a high gate turn off current with a peak amplitude of 20-35 percent of the anode to cathode current (current to be controlled). An MTO contains two control terminals, one for the turn-on gate and one for the turn-off gate, also known as the MOSFET gate. To activate an MTO, a sufficiently large gate pulse is given, causing the thyristor to latch on (similar to SCR and GTO). A voltage pulse is applied to the MOSFET gate to turn off the MTO. When the MOSFET switches on, it shorts the NPN transistor's emitter and base, preventing latching. It's a considerably faster operation than a GTO (around 1-2 s), in which the huge negative pulse sent to the GTO's gate seeks to extract enough current from the NPN transistor's base. Furthermore, the shorter time (MTO) eliminates the losses associated with current transfer. MTOs are employed in high voltage applications ranging from 20 MVA to motor drives, flexible AC line transmissions (FACTs), and high power voltage source inverters. GTOs are utilized in DC and alternating current motor drives, high power inverters, and alternating current stabilizing power. 3.Emitter turn off thyristors (ETO)The ETO, like the MTO, has two terminals, one for a regular gate and one for a second gate connected in series with a MOSFET.Positive voltages are provided to both gates to turn on an ETO, which causes NMOS to turn on and PMOS to switch off. The ETO turns on when a positive current is introduced into the usual gate.NMOS turns off and transfers all current away from the cathode when a negative voltage signal is supplied to the MOSFET gate. The latching process is terminated, and the ETO is turned off.ETOs are used in high-power voltage source inverters, Flexible AC line Transmissions (FACTs), and Static Synchronous Compensators (STATCOM). 6.3 Bidirectional controlSo far, the thyristors that have been discussed have been unidirectional and have been employed as rectifiers, DC-DC converters, and inverters. To use these thyristors for AC voltage control, two of them must be coupled in anti-parallel, resulting in two independent control circuits with extra wire connections. Bidirectional thyristors, which can conduct current in both directions when triggered, were created expressly to address this issue. 1. Triode for alternating current (TRIAC)After SCRs, TRIACS are the most often utilized thyristors. They can regulate both half of the alternating waveform, allowing for more efficient use of available power. TRIACs, on the other hand, are normally only employed for low power applications due to their inherent non-symmetrical structure. When switching at various gate voltages throughout each half cycle, TRIACs have some drawbacks in high power applications. This generates more harmonics in the system, causing an imbalance and affecting EMC performance.Low-power TRIACs are utilized in light dimmers, speed controllers for electric fans and other electric motors, and computerized control circuits for household appliances. 2. Diode for alternating current (DIAC)DIACS are low-power devices that are typically used in tandem with TRIACS (placed in series with the gate terminal of a TRIAC). Because TRIACS are inherently unsymmetrical, a DIAC stops any current from flowing through the TRIAC's gate until the DIAC reaches its trigger voltage in either direction. This guarantees that TRIACS used in AC switches trigger in both directions uniformly. Light bulb dimmers contain DIACs. 3. Silicon Diode for Alternating Current (SIDAC)Electrically, a SIDAC behaves similarly to a DIAC. SIDACs offer a higher breakover voltage and stronger power handling capabilities than DIACs. A SIDAC is a five-layer device that can be used as a switch on its own rather than as a trigger for another switching device (like DIACs are for TRIACS). A SIDAC begins to conduct current if the applied voltage matches or exceeds the breakover voltage. Even if the applied voltage changes, it remains in this conducting state until the current can be decreased below the rated holding current. The SIDAC then returns to its nonconductive condition to begin the cycle again. SIDACs are found in relaxation oscillators and other specialized devices. Ⅶ Thyristor VS TransistorsBoth thyristors and transistors are electrical switches, however thyristors have a much higher power handling capacity than transistors. Because of the Thyristor's high rating in kilowatts, whereas transistor power ranges in watts. In this analysis, a Thyristor is modeled as a closed couple pair of transistors. The major difference between a transistor and a thyristor is that a transistor requires constant switching power to stay on, but a thyristor requires only a single trigger to stay on. Transistors cannot be used in applications such as alarm circuits that must activate once and remain ON indefinitely. To address these issues, we employ the Thyristor. More distinctions between Thyristor and Transistor are listed in the table below: PropertyThyristorTransistorLayerFour LayersThree LayersTerminalsAnode, Cathode and GateEmitter, Collector, and BaseOperation over-voltage and currentHigherLower than thyristorTurning ONJust required a gate pulse to turn ONRequired continuous supply of the controlling currentInternal power lossLower than transistorhigher Ⅷ ConclusionSilicon Controlled Rectifiers, also known as Thyristors, are three-junction PNPN semiconductor devices that can be thought of as two interconnected transistors capable of switching high electrical loads. They can be latched-"ON" with a single positive current pulse delivered to their Gate terminal and will remain "ON" endlessly until the Anode to Cathode current falls below their minimum latching level. Thyristors are high-speed switches that can be used to replace electromechanical relays in a variety of circuits since they have no moving components, no contact arcing, and are not affected by corrosion or dirt. However, in addition to merely switching big currents "ON" and "OFF," thyristors can be used to adjust the mean value of an alternating current load current without dissipating large quantities of electricity. The regulation of electric lighting, heaters, and motor speed is a good example of thyristor power control. Ⅸ Frequently Asked Questions about Thyristor1. What is the difference between SCR and thyristor?A thyristor is a four-layer semiconductor device with three PN junctions. It is also referred to as "SCR" (Silicon Control Rectifier). The phrase "Thyristor" is a combination of the words thyratron (a gas fluid tube that functions as an SCR) and transistor. Thyristors are also referred to as PN PN Devices. 2. Why SCR is called thyristor?A silicon controlled rectifier (SCR) is a unidirectional silicon semiconductor device. Because this device is the solid-state analogue of a thyratron, it is also known as a thyristor or thyroid transistor. 3. Is thyristor a semiconductor device?A thyristor is a four-layer semiconductor device that alternates between P-type and N-type materials (PNPN). A thyristor is typically composed of three electrodes: an anode, a cathode, and a gate (control electrode). 4. What is the symbol for a thyristor?The silicon-controlled rectifier, SCR, or thyristor symbol used in circuit designs or circuits aims to highlight the rectifier properties while also displaying the control gate. As a result, the thyristor symbol resembles a typical diode with a control gate entering at the junction. 5. What is the difference between diode and thyristor?The primary distinction between a diode and a thyristor is that a diode has two terminals and is employed as a rectifier for converting AC to DC as well as a switch. The thyristor, on the other hand, has two terminals and functions as a switch. Both a diode and a thyristor are semiconductor devices made of a combination of p and n materials. 6. How is thyristor measured?In general, the multimeter is used to measure the DC resistance between the anode and cathode of thyristors and diodes, as well as the gate to the cathode on thyristors. These data are of the device's "off state" or blocking voltage. "Open circuit" and "short circuit" are the only valid readings. 7. How to Check a Thyristor?1)Connect the anode (entry terminal) of the thyristor to the multimeter's positive (red) lead.2)Place the multimeter in the high resistance mode.3)Replace the leads in their original placements, adding the gate terminal to the positive lead this time. 8. How do I know if my thyristor is bad?Connect the negative lead of your ohmmeter to the SCR's anode and the positive lead to the SCR's cathode. Take note of the resistance value displayed on the ohmmeter. It should display a very high resistance value. If it reads an extremely low value, the SCR is shorted and needs to be replaced. 9. Which is better IGBT or thyristor?IGBTs are much faster than typical thyristors and can be controlled by toggling an on/off gate signal with a digital signal processor and a field-programmable gate array rather than waiting for a zero crossing. The conduction losses and switching losses are the two primary losses for the IGBT. 10. What is the purpose of a thyristor in a circuit?A thyristor's principal function is to control electric power and current by acting as a switch. It provides adequate protection to circuits with high voltages and currents for such a compact and lightweight component (up to 6000 V, 4500 A). 

Introduction FPGA is a product of further development on the basis of programmable devices such as PAL, GAL, and CPLD. It appears as a semi-custom circuit in the field of application specific integrated circuits (ASIC), which not only solves the shortcomings of the custom circuit, but also overcomes the limited number of gate circuits of the original programmable device. FPGA is often used in communication, network and other fields to process a large number of network data packets. It is also widely used in aerospace, military defense and other fields. As a hardware test platform before other chips are taped out, it plays an important role in cloud computing, artificial intelligence (AI) and other fields. FPGA Applications, Features and Selection Catalog Introduction Ⅰ FPGA Basic Architecture Ⅱ FPGA Basic Features Ⅲ FPGA Applications 3.1 Circuit Design 3.2 Product Design 3.3 System Application Ⅳ Vacuum Cleaner Based on FPGA 4.1 A Short Brief 4.2 The Composition of the Platform 4.3 Main Hardware Design 4.4 Program Design Points Ⅴ FAQ Ⅰ FPGA Basic Architecture FPGA consists of 6 parts, namely programmable input/output (I/O) unit, basic programmable logic unit, embedded RAM, abundant wiring resources, bottom embedded functional unit and embedded dedicated hard core. Figure 1. FPGA Basic Architecture Each unit is described as follows:🔺Programmable I/O UnitAt present, most FPGA I/O units are designed in programmable mode, that is, through the flexible configuration of software, they can adapt to different electrical standards and I/O physical characteristics; the matching impedance characteristics, the pull-up and pull-down resistors can be adjusted; the output drive current can be adjusted, etc.🔺Basic Programmable Logic UnitThe basic programmable logic unit of FPGA is composed of a look-up table (LUT) and a register. The look-up table completes the pure combinational logic function. FPGA internal registers can be configured as flip-flops with synchronous/asynchronous reset and set, clock enabled, or as latches. FPGA generally relies on registers to complete synchronous sequential logic design. Generally speaking, the configuration of a classic basic programmable unit is a register plus a LUT. However, the internal structures of registers and look-up tables of different manufacturers are different, so the combination modes are also different.An important aspect of learning the LUT and Register ratios of the underlying hive is device selection and sizing. In addition to the basic programmable logic units inside the FPGA, there are embedded RAM, PLL or DLL, dedicated Hard IP Core, etc. These modules can also be equivalent to a certain scale of system gates, so the simple and scientific method is use the number of Registers or LUTs of the device to measure.🔺Embedded RAMNow most FPGAs have embedded RAM, which can be configured as single-port RAM, dual-port RAM, pseudo-dual-port RAM, CAM, FIFO and other storage structures.CAM is the content address memory. The data written to the CAM is compared with every data stored in it and returns the addresses of all internal data that are the same as the port data. Simply put, RAM is a storage unit for writing addresses and reading data, while CAM is just the opposite of RAM. In addition to block RAM, Xilinx and Lattice FPGAs can flexibly configure LUTs into storage structures such as RAM, ROM, and FIFO.🔺Rich Wiring ResourcesThe routing resources connect all the units in the FPGA, and the length and process of the connection determine the driving ability and transmission speed of the signal on the connection. Here the division of wiring resources:1) Full dedicated routing resources: Complete the routing of the global clock and global reset/set within the device.2) Long-term resources: Used to complete the wiring of some high-speed signals and some second global clock signals between device banks.3) Short-circuit resources: Used to complete the logic interconnection and wiring between basic logic units.4) Others: There are various wiring resources and control signal lines such as dedicated clock and reset in the logic unit.In the design process, the place and router often automatically selects the available routing resources to connect the underlying unit modules used according to the topology and constraints of the input logic netlist, so routing resources are often ignored. In fact, the optimization of routing resources is directly related to the use and implementation results.🔺The bottom layer is embedded with functional units, and the resources embedded by different manufacturers will be different.🔺Embedded dedicated hard coreDifferent from the "low-level embedded unit", the hard cores here are mainly those with relatively weak generality, and not all FPGA devices contain hard cores.   Ⅱ FPGA Basic Features 1) Using FPGA to design ASIC circuit (application-specific integrated circuit), users can get suitable chips without film production.2) FPGA can be used as a mid-scale sample for other full-custom or semi-custom ASIC circuits.3) There are abundant triggers and I/O pins inside the FPGA.4) FPGA is one of the devices with the shortest design cycle, the lowest development cost and the lowest risk in the ASIC circuit.5) FPGA adopts high-speed CMOS technology with low power consumption and is compatible with CMOS and TTL levels. Figure  2. FPGA Chip Ⅲ FPGA Applications 3.1 Circuit Design Connection logic and control logic are the areas where FPGA played a relatively important role in the early days and are also the cornerstone of FPGA applications. In fact, it is still quite difficult to apply FPGA in circuit design, which requires developers to have corresponding hardware knowledge (circuit knowledge) and software application capabilities (development tools). So talents in this area are always in short supply, and they are often engaged in new technologies. The successful product development of new products will become the mainstream basic products in the market for designers to apply. In the near future, the design of general-purpose and special-purpose IP will become popular. 3.2 Product Design Apply relatively mature technology to some specific fields such as communication, video, information processing, etc. to develop products that meet the needs of the industry and can be accepted by industry customers. This aspect is mainly a combination of FPGA and professional technology. In addition, there are product design for interface issues with professional customers also includes professional tool products and civilian products. The former focuses on performance, while the latter focuses on price-sensitive product design to achieve product functions as the main purpose.FPGA is a means of realization. In this field, it has the characteristics of interface, control, functional IP, embedded CPU, etc. to realize a system product design with simple structure, high degree of curing, and comprehensive functions for FPGA market. 3.3 System Application The system-level application is the combination of FPGA and traditional computer technology to realize an FPGA version of the computer system. For example, Xilinx V-4, V-5 series FPGA is used to realize the embedded POWER PC CPU, and then cooperate with various peripheral functions. To achieve a basic environment, running LINUX and other systems on this platform also supports various standard peripherals and functional interfaces, which is very helpful for quickly forming large-scale FPGA systems.In system-level applications, if the developers do not have the ability to expand the system, it is meaningless to just engage in programming. Of course, the development of device drivers is another case. The system-level application seems to have a high starting point, but it does not have deep development ability, it is likely to become a hobbyist, just like many people can make web pages but cannot be called programming.   Ⅳ Vacuum Cleaner Based on FPGA 4.1 A Short Brief Design of indoor intelligent vacuuming platform based on FPGA.Intelligent environmental cleaners have increasingly become the focus of research because they can replace people in environmental cleaning. Although they achieve intelligence, most of them have complex structures and high integration, which are not conducive to developers to expand their functions. On the basis of researching and summarizing the relatively mature products on the market, this paper designs and implements an indoor intelligent vacuuming platform based on a highly programmable FPGA. The platform has self-navigation, can clean most of the space, and is compact in shape, stable in operation and low in noise. More importantly, it has a simple structure and a user-friendly interface, which is convenient for further development of operation and functions. Figure  3. Body Frame 4.2 The Composition of the Platform The overall frame design of the platform proposed in this paper is shown in Figure 3, and a car with four wheels is used as the carrier of the entire platform. The FPGA controller is used as the main controller of the entire platform, and is connected to the photoelectric sensors jk1, jk2, jk3, jk4 and the collision switch jk5 through I/O to realize the detection of platform obstacles. Then output PWM waveform through I/O to drive speakers and high-low, and the change of the level drives the on and off of the LED to form an acousto-optic circuit. Finally the stepper motor dj1, dj2 and the DC dust collection motor dj3 are driven by controlling the signal control line of the motor driver to realize the movement and dust collection of the platform. 4.3 Main Hardware Design The system is mainly composed of FPGA main control chip, photoelectric sensor, collision switch, wireless remote control transmitter module controlled by two STC89C52 microcontrollers, two mode selection chips, acousto-optic circuit, drive motor, vacuum cleaner motor and the power supply circuit of the whole system, such as as shown in the Figure 4. Figure  4. Main Control System 🔺FPGA Chip SelectionAccording to the overall design of the platform, the basic requirements for the chip can be drawn:(1) At least 6 PWM waveform outputs are required.(2) One serial communication interface is required.(3) A real-time chip that requires a higher 12 V to be converted to 3.3 V.(4) Higher processing speed.(5) There are more I/O interfaces.Taking these conditions into consideration, the EP2C35F672C6 model in the CycloneII series FPGA produced by Altera can basically meet the requirements. It has excellent operation speed, low cost and DSP module, large internal memory, multi-channel PWM output, flexible design and comprehensive use of multiple languages, and the cost performance is relatively high.🔺Configuration Circuit Design Points(1) Power supply circuit: The power supply system uses 12V power supply as the input power supply, uses L7805CV to step down it to 5V, and then converts 5V to 3.3V and 1.2V by TPS37HD301. The power supply point of the I/O port of the FPGA is 3.3V, the core supply voltage is 1.2V. Because the motor drive system uses the 5V signal of the controller, and the port voltage of the FPGA is 3.3V, the I/O voltage must be boosted to 5V, and the 74HCT245 boost chip is used here.(2) Clock and reset circuit: ZPB-26-16 M is an active crystal oscillator in the clock circuit, and the frequency is 16MHz, which makes the serial port baud rate more accurate. At the same time, it can support the PPL function and ISP download function inside the chip. The reset circuit takes hardware reset and software reset.(3) Debug JTAG and download circuit: Because the soft core ISP and JTAG can be built directly inside the FPGA, the hardware circuit is connected to a JTAG interface of IDC-10.(4) Configuration storage circuit: EPCS16 is selected as the ROM of the FPGA, which can be repeatedly programmed by the download cable or other equipment, and can also be programmed online through the AS interface. Use the 4MHz On-Chip memory inside the FPGA chip as the RAM of the FPGA.(5) Sensor and collision switch: E3F-DS5C4.P1R photoelectric switch, used to detect obstacles and stairs, which is a cylindrical diffusion type with a maximum distance of 5cm, or an adjustable NPN type normally open photoelectric switch. The collision switch mainly cooperates with the front sensor to protect the front of the platform. When the platform hits the obstacle ahead, trigger the switch to make the platform avoid the obstacle.(6) Wireless sending and receiving module: XL02-232AP1 wireless module is a half-duplex wireless transmission module with UART interface, which can work in the 433MHz public frequency band and meet the wireless regulatory requirements.(7) Drive and vacuum motor: The platform adopts the front wheel dual drive, the motor selects the two-phase hybrid stepping type, and the vacuum cleaner motor adopts the DC motor. The main electrical parameters of the stepping motor are: ① Step angle: 1.8°② Phase current: 0.87 A③ Holding torque: 0.24 nm④ Phase resistance: 3.3 Ω⑤ Phase inductance: 5.0 mH⑥ Weight: 0.2 kg(8) Sound and light circuit and automatic cleaning time input display circuit: The sound and light circuit is mainly composed of light-emitting diodes and buzzers, which are directly connected to the FPGA to remind the working state of the platform. Use 4 buttons (OK, Initial, Up, Down) to input the cleaning time, and then three digital tubes display the set time. The cleaning time is counted by the timer inside the FPGA. When the timer is completed, the platform stops working. 4.4 Program Design Points Divide the program into two parts: hardware programming and software programming. For hardware programming, timing simulation of hardware circuits is required to determine the effect of debugging.🔺Hardware Programming and SimulationThe platform mainly generates input signals through sensors and collision switches, and processes the signals through FPGA. Finally, the FPGA transmits the processed signals to the motor, and the motor completes a series of actions, as shown in Table 1. So its logic design is the key to realize intelligence. After the hardware selection is completed, use Quartus II to build the hardware schematic diagram. After compiling, perform timing simulation on jk1, jk2, jk3, and jk4, analyze the timing relationship, estimate the performance of the design, and check and eliminate competition risks.Table 1: Relationship between Motor Status and Platform Working Status. dj1 dj2 dj3 Cleaner Status Turn Forward Turn Forward ON Vacuuming Forward Turn Back Turn Forward ON Vacuuming Left Turn Forward Turn Back ON Vacuuming Right Turn Back Turn Back ON Vacuuming Back The realization of platform work in automatic cleaning mode depends on the cooperative work of sensors (jk1, jk2, jk3, jk4) and motors (dj1, dj2, dj3), and the logical relationship is designed according to their functions.Table 2: Relationship between Sensor Status and Platform Working Status. jk1 jk2 jk3 jk4 Cleaner Status 1 1 1 1 Vacuuming Forward 1 1 0 1 Vacuuming Left 1 0 1 1 Vacuuming Right 1 0 0 1 Vacuuming Forward 0 1 0 1 Vacuuming Forward (Turn 90° Left)  0 0 1 1 Vacuuming Forward (Turn 90° Right)  0 0 0 1 Vacuuming Back When the hardware selection is completed, use Quartus II to build the hardware schematic diagram. After compiling, perform timing simulation on jk1, jk2, jk3, and jk4 to analyze the timing relationship.🔺Software ProgrammingAfter the hardware design and debugging is completed, the software system design is also carried out. Write a C program in a C language file to program the SoPC. The overall algorithm flow of the platform work is shown in Figure 5. When the platform is powered on, firstly enter the automatic cleaning and manual remote cleaning mode. After the automatic cleaning mode is selected, input the working time of the platform's automatic cleaning through the keyboard, and use the sensor to judge whether it encounters obstacles or stairs during the cleaning process. Through the interrupt, check whether the set time is reached at all times. If not, the program will return to running. However, if the set time is up, the program will end and the platform will stop working. When remote cleaning is selected, platform movement is controlled by the operator. Figure 5. Algorithm Flowchart Through hardware selection, construction and debugging, and software language writing and debugging, a simple platform has been successfully made, and various predetermined functions have been realized. Compared with similar products on the market, its structure is simpler, the cost is lower, the flexibility and scalability are stronger, and it provides a hardware-supported platform for researchers to develop more functions, which has practical value. As microprocessors continue to advance and sensing technology evolves, their performance can continue to improve and costs can continue to decline. However, in the process of simulation and implementation, it is found that its specific process algorithm is not rigorous enough, and it is necessary to continue to improve it in the future.   Ⅴ FAQ 1. What is FPGA architecture?The field-programmable gate array (FPGA) is an integrated circuit that consists of internal hardware blocks with user-programmable interconnects to customize operation for a specific application. 2. What are the parts of an FPGA?Structure of an FPGAConfigurable Logic Block (CLB)Digital Signal Processing (DSP) Slice.Transceivers.Block Random Access Memory (BRAM)Input/Output (IO) Blocks. 3. What is a basic unit of an FPGA?The configurable logic blocks (CLBs) are the basic logic unit of an FPGA. Sometimes referred to as slices or logic cells, CLBs are made up of two basic components: flip-flops and lookup tables (LUTs). 4. What is FPGA and its types?FPGA stands for Field Programmable Gate Array which is an IC that can be programmed to perform a customized operation for a specific application. They have thousands of gates. In the field of VLSI FPGAs have been very popular. 5. What is the function of FPGA?FPGAs are mainly used to design application-specific integrated circuits (ASICs). First, you design the architecture of such a circuit. Then, you use an FPGA to build and check its prototype. Errors can be corrected. 6. What is FPGA and its application?The FPGA is Field Programmable Gate Array. It is a type of device that is widely used in electronic circuits. FPGAs are semiconductor devices which contain programmable logic blocks and interconnection circuits. It can be programmed or reprogrammed to the required functionality after manufacturing. 7. What are the advantages of FPGA?FPGA advantagesLong-term availability.Updating and adaptation at the customer.Very short time-to-market.Fast and efficient systems.Acceleration of software.Real-time applications.Massively parallel data processing. 8. What is inside CLB in FPGA?A configurable logic block (CLB) is the basic repeating logic resource on an FPGA. When linked together by routing resources, the components in CLBs execute complex logic functions, implement memory functions, and synchronize code on the FPGA. 9. What are the main applications of FPGAs?Main FPGA applications are: Medical, video & image processing, telecom & datacom, server & cloud and defense and space. FPGA chips are used in both wired and wireless communications. 10. What are the industrial applications of FPGA boards?Such applications include multiple sensor dome cameras, HD (High Definition) cameras, night-vision cameras, etc. FPGAs provide the differentiation factor and the processing power to implement such complex solutions. 11. What are the applications of CPLDs and FPGAs?Applications of CPLDCPLDs can be used as bootloaders for FPGAs and other programmable systems. CPLDs are often used as address decoders and custom state machines in digital systems. Due to their small size and low power consumption, CPLDs are ideal for use in portable and handheld digital devices. 12. What programmable technology is used in a FPGA devices?FPGA emerged from relatively simpler technologies such as programmable read-only memory (PROM) and programmable logic devices (PLDs) like PAL, PLA, or Complex PLD (CPLD). It consists of three main parts: Configurable Logic Blocks — which implement logic functions. Programmable Interconnects — which implement routing. 13. What are the features of FPGA?The basic features of FPGA are: 1) FPGA design ASIC circuit, the user does not need to chip production, you can get a combination of chips. - 2) FPGA can do all other custom or semi-custom ASIC circuit of the sample sample. 3) FPGA has a rich internal trigger and I / O pin. 14. Is a FPGA a computer?An FPGA is a chip consisting of a series of logic blocks which can be modified and configured by the user. ... FPGA are programmable chips and their functionality can be updated multiple times. FPGAs come in array of size and prices and are most likely used in low-mid size volume products.

Introduction Capacitors are the most common passive components used in circuit design. Its function is to block the AC current while pass the DC current, and it also has the function of power storage, and has a good filtering effect, which can output the pulsating signal in a smooth way. The application of capacitors in electronics is very common. Let's talk about the common types of capacitor in circuits and their uses. Basic Introduction to Capacitors Catalog Introduction Ⅰ Types of Capacitors in Use with Models 1.1 Ceramic Capacitors (CC) 1.2 Polyester Capacitor (CL) 1.3 Polystyrene Capacitors (CB) 1.4 Polypropylene Capacitors (CBB) 1.5 Monolithic Ceramic Capacitor (MLCC) 1.6 Mica Capacitors 1.7 Paper Capacitors (CZ) 1.8 Metallized Paper Capacitors (CJ) 1.9 Aluminum Electrolytic Capacitors (CD) 1.10 Tantalum Electrolytic Capacitors (CA) 1.11 Mica Trimmer Capacitors (CY) 1.12 Ceramic Trimmer Capacitors (CC) 1.13 Film Trimmer Capacitors 1.14 Air Variable Capacitor (CB) 1.15 Film Variable Capacitors Ⅱ FAQ Ⅰ Types of Capacitors in Use with Models Virtually all types of capacitor are available as following: 1.1 Ceramic Capacitors (CC) 🔺Material: Use ceramic material as medium, coat a layer of metal (silver) film on its surface, and then sinter at high temperature as an electrode. Ceramic capacitors are divided into Class 1 dielectrics (NPO, CCG); Class 2 dielectrics (X7R, 2X1) and Class 3 dielectrics (Y5V, 2F4).🔺Types: Ceramic capacitors are divided into two types: high-frequency ceramics and low-frequency ceramics. Capacitors with a small positive temperature coefficient of capacitance are used in highly stable oscillation circuits as loop capacitors and pad capacitors. Low-frequency ceramic capacitors are limited to bypassing or blocking DC in circuits with lower operating frequencies, or occasions (including high frequencies) that do not require high stability and loss. Such capacitors should not be used in pulsed circuits because they are prone to breakdown by pulsed voltages.🔺Features: Class 1 have the advantages of small temperature coefficient, high stability, low loss and high withstand voltage. The maximum capacity does not exceed 1000pF, commonly used are CC1, CC2, CC18A, CC11, CCG and other series. Mainly used in high frequency circuits.Class 2 and Class 3 are characterized by high dielectric coefficient, large capacity (up to 0.47μF), small volume, and poor loss and insulation compared to Class 1. 🔺Application Models: Widely used in medium and low frequency circuits for DC blocking, coupling, bypassing and filtering capacitors, and commonly used are CT1, CT2, CT3 and other three series. 1.2 Polyester Capacitor (CL) 🔺Material: A non-polar capacitor with a positive temperature coefficient (that is, when the temperature increases, the capacitance becomes larger) made of polar polyester film as the medium.🔺Advantages: High temperature resistance, high pressure resistance, moisture resistance and cheap price, suitable for bypass capacitors.🔺Application Models: Generally used in medium and low frequency circuits, and commonly used models are CL11, CL21 and other series.🔺Value Identification: Internationally, the withstand voltage value of capacitors is usually represented by letters. The common correspondence between codes and bases is:A: 1.0; B: 1.25; C: 1.6; D: 2.0; E: 2.5; F: 3.15; G4.0;H: 5.0; J: 6.3; K: 8.0; Z: 9.0;The number in front of the letter represents the power of 10, for example, 2A is 102*1.0=100V, 2C is 102*1.6=160V and so on.The letters behind the withstand voltage value represent the capacitance in pF.For example, 823 means the capacity is 82*10^3=82000Pf, 224 means 22*104=220000pf=0.22μF. The last letter means the precision, such as J means the capacity tolerance is ±5% and so on.Typical capacitor identification example: 2A823J is 82000Pf±5%, withstanding voltage 100V. 1.3 Polystyrene Capacitors (CB) 🔺Material: There are two types of foil type and metallized type.🔺Advantages: Foil type has large insulation resistance, low dielectric loss, stable capacity and high precision, but large volume and poor heat resistance; metallized type has good moisture resistance and stability, and can recover after breakdown, also it has advantages of the low insulation resistance and poor high frequency characteristics.🔺Application Models: Generally used in medium and high frequency circuits, and commonly used models are CB10, CB11 (non-sealed foil type), CB14~16 (precision type), CB24, CB25 (non-sealed metallization), CB80 (high pressure type), CB40 (sealed metallization) and other series. In short, they used in various precision measuring instruments, car radios, industrial proximity switches and high-precision digital-to-analog converter circuits. 1.4 Polypropylene Capacitors (CBB) 🔺Material: It is a negative temperature coefficient non-polar capacitor that made of non-polar polypropylene film as the medium. There are two types of unsealed (commonly encapsulated with colored resin paint) and sealed (encapsulated with metal or plastic housing).🔺Advantages: Small loss, stable performance, good insulation and large capacity.🔺Application Models: Generally used in medium and high frequency circuits or as starting capacitors for motors, and commonly used foil polypropylene capacitors include CBB10, CBB11, CBB60, CBB61, etc.; metallized polypropylene capacitors include CBB20, CBB21, and CBB401 series.CBB capacitor series are used in high frequency and high power circuits such as filtering, cross-line, resonance, etc. 1.5 Monolithic Ceramic Capacitor (MLCC) 🔺Material: Multi-layer laminated ultra-miniature capacitors sintered with barium titanate-based ceramic materials.🔺Advantages: It has the advantages of reliable performance, high temperature resistance, moisture resistance, large capacity (range 1pF~1μF), and small leakage current.🔺Disadvantages: Low working voltage (withstand voltage lower than 100V).🔺Application Models: Widely used in resonance, bypass, coupling, filtering, etc, and commonly used are CT4 (low frequency), CT42 (low frequency), CC4 (high frequency), CC42 (high frequency) and other series.🔺ClassificationClass 1It is a temperature-compensated NPO dielectric. The electrical performance of this capacitor is the most stable and basically does not change with temperature, voltage and time. In short, it is an ultra-stable, low-loss capacitor material type and is suitable for high stability and reliability requirements. frequency, UHF and VHF circuits.Class 2It is a high dielectric constant X7R series, so it can make capacitors with larger capacity than NPO dielectrics. This kind of capacitor has relatively stable performance. With the change of temperature, voltage and time, its unique performance does not change significantly. It is a type of stable capacitor material. It is used in DC blocking, coupling, bypass, filter circuit and frequency circuit with high reliability requirements.Class 3It uses Y5V dielectric. This capacitor has a high dielectric constant and is often used in the production of large-capacity capacitors with larger specific capacitance and higher nominal capacity. However, its capacity stability is worse than that of X7R, and its capacity and loss are more sensitive to test conditions such as temperature and voltage. It is mainly used in oscillation, coupling, filtering and bypass circuits in electronic complete machines.Monolithic ceramic capacitors are larger than ordinary ceramic capacitors (10pF~10μF), and have the advantages of large capacitance, small size, high reliability, stable capacitance, high temperature resistance, good insulation, and low cost, so they are widely used. They can not only replace mica capacitors and paper capacitors, but also replace some tantalum capacitors, and are widely used in small and ultra-small electronic devices (such as liquid crystal watches and micro instruments). 1.6 Mica Capacitors 🔺Material: Mica is used as the medium, and a layer of metal film (silver) is sprayed on the surface as the electrode, which is laminated according to the required capacity and then dipped and compressed in the bakelite shell (or ceramic or plastic shell).🔺Advantages: Good stability, small distributed inductance, high precision, low loss, large insulation resistance, good temperature characteristics, that is, good frequency characteristics, high operating voltage (50V~7kV) and so on.🔺Application: It is generally used for signal coupling, bypassing, tuning, etc. in high-frequency circuits. For example, they are common in occasions that require high stability and reliability of capacitors, such as instruments and meters of electronic, power and communication equipment, and are also used in aerospace, aviation, navigation, rockets, satellites, military electronics, and oil exploration equipment. Commonly used ones are CY, CYZ, CYRX and other series. 1.7 Paper Capacitors (CZ) 🔺Material: The thin capacitor special paper is used as the medium, and the aluminum foil or lead foil is used as the electrode.🔺Advantages: The capacitance (100pF~100μF) has a wide working voltage range, and the maximum withstand voltage value can reach 6.3kV.🔺Disadvantages: Large size, low capacity accuracy, large loss, and poor stability.🔺Classification: Paper capacitors are divided into inductive type and non-inductive type according to winding methods. The inductive core is actually a ribbon coil with many turns, so the inductance is large. The non-inductive type is to stagger the electrode foils to both sides of the paper, so that the sides of the foil strips extend out of the paper strips, and then the leads are welded after winding into a cylindrical core. In this way, the coils of the electrode foil are short-circuited with each other, so the inductance is very small. This capacitor can be used at higher frequencies.🔺Application Models: Common ones are CZ11, CZ30, CZ31, CZ32, CZ40, CZ80 and other series. 1.8 Metallized Paper Capacitors (CJ) 🔺Material: Using vacuum evaporation technology, a layer of metal film is evaporated on the paper coated with paint film as an electrode.🔺Advantages: Compared with ordinary paper capacitors, it is small in size, large in capacity, and has strong recovery ability after breakdown, which is an unique characteristic. For common situation, when the paper-dielectric capacitor is broken down, the paper medium is scorched, and the two layers of metal foil are melted together at the breakdown place to form a short circuit. But for metallized paper capacitors, the metal film at the breakdown place evaporates at high temperature, leaving only insulating holes and no short circuit.🔺Application Models: Common ones are CJ10, CJ11 and other series. 1.9 Aluminum Electrolytic Capacitors (CD) 🔺Material: The polar one is made by winding the aluminum foil (positive electrode) with an oxide film and the backing paper impregnated with the electrolyte solution together with the cathode foil lamination. Appearance package has tube type and vertical type. And there is a blue or black plastic cover outside the aluminum shell.🔺Advantages: The capacity range is large, generally 1~10000μF, and the rated working voltage range is 6.3V~450V.Disadvantages: Medium loss, large capacity error (maximum allowable deviation is +100%, -20%), poor high temperature resistance, long storage time and unstable working state.🔺Application: Usually used in DC power circuits or medium and low frequency circuits for filtering, decoupling, signal coupling, time constant setting, and DC blocking. Note that the polarity cannot be reversed when used as a filter capacitor in a DC power supply.Selection: The capacity and withstand voltage marked on the body of the aluminum electrolytic capacitor are very important and are the most basic content for selecting capacitors. In the actual selection of capacitors, a capacitor with a larger capacity should be used for places where the current changes rapidly, but it’s not always good. First, the larger the capacity, the higher the cost and volume. In addition, the larger the capacitor, the higher the charging current. The bigger it is, the longer the charging time will be. These are all to be considered in practical application selection. 1.10 Tantalum Electrolytic Capacitors (CA) 🔺Material: There are two forms:1) The foil type tantalum electrolytic capacitor adopts a winding core inside, the negative electrode is liquid electrolyte, and the medium is oxidized tantalum. Common models are CA30, CA31, CA35, CAk35 series.2) The tantalum powder sintered positive electrode is sintered with very fine tantalum powder blocks. Packaging comes in many forms. Widely used models include CA41, CA42, CA42H, CA49, CA70 (non-polar) and other series.🔺Advantages:1) Small SizeSince capacitors use tantalum powder with very fine particles, and the dielectric constant ε of the tantalum oxide film is 17 higher than that of the aluminum oxide film, the capacitance per unit volume of the tantalum capacitor is large.2) Wide Operating Temperature RangeGenerally, tantalum electrolytic capacitors can work normally under the temperature of -50℃~100℃. Although aluminum electrolytic capacitors can also work in this range, their electrical performance is far inferior to that of them.3) Long Life, High Insulation Resistance and Small Leakage CurrentThe tantalum oxide film dielectric in tantalum electrolytic capacitors is not only resistant to corrosion, but also maintains good performance for a long time.4) Good Impedance Frequency CharacteristicsFor capacitors with poor frequency characteristics, when the operating frequency is high, the capacitance drops significantly, and the loss (tgδ) also rises sharply. But solid electrolytic capacitors can work above 50kHz. As the frequency increases, the capacity of capacitors also decreases, but the decrease is small. Some data show that the capacity decreases by less than 20% when working at 10kHz, while the capacity of aluminum electrolytic capacitors decreases by 40%.5) High ReliabilityThe chemical properties of the tantalum oxide film are stable, and because the tantalum anode substrate Ta2O5 is resistant to strong acids and alkalis, it can use solid or acid-containing liquid electrolytes with low resistivity, which makes the loss of tantalum electrolysis smaller than that of aluminum electrolytic capacitors, and the temperature stability is good.🔺Disadvantages: High production cost and low pressure resistance.🔺Application: Widely used in various medium and low frequency circuits and time constant setting circuits in communications, aerospace, military and household appliances.With the properties of storing electricity, charging and discharging, etc, they are mainly used in filtering, energy storage and conversion, mark bypass, coupling and decoupling, and time constant components. Pay attention to its performance characteristics in application, and correct use will help to give full play to its functions, such as considering the working environment of the product and its heating temperature, and taking measures such as derating, if it is used improperly, it will affect the service life of the product.   A variable capacitor is a capacitor whose capacitance can be adjusted within a certain range. When the relative effective area between the pole pieces or the distance between the pieces changes, its capacitance changes accordingly. Usually used as a tuning capacitor in a radio receiving circuit. Here are several types as following: 1.11 Mica Trimmer Capacitors (CY) 🔺Material: It consists of a fixed piece and a moving piece. The fixed piece is a metal piece, and a layer of mica flakes is the most medium on its surface. The moving piece is an elastic copper or aluminum piece. Adjust the moving piece and the fixed piece by adjusting the screws on the moving piece, then the distance between the slices changes the capacitance. There are single trimmers and double trimmers.🔺Advantages: The capacitance can be adjusted repeatedly.🔺Application: Used in transistor radios, electronic instruments, and electronic equipment. 1.12 Ceramic Trimmer Capacitors (CC) 🔺Material: Ceramic is used as the medium, and the semicircular silver layer is plated on both the moving plate and the stator. By rotating the moving plate to change the relative position between the two silver plates, the size of the capacitance can be changed.🔺Advantages: Small size, can be adjusted repeatedly, easy to use.🔺Application: Used in transistor radios, electronic instruments, and electronic equipment. 1.13 Film Trimmer Capacitors 🔺Material: Use organic plastic film as a medium, that is, add it between the moving piece and the fixed piece. Adjust the screw on the moving piece, and make the moving piece rotate to change the capacity. Film trimmer capacitors are generally divided into double trimmers and quadruple trimmers. Some sealed double-connected or four-connected variable capacitors have their own thin-film trimmer capacitors, which are installed on the top of the casing, making it easier to use and adjust.🔺Advantages: With small size, light weight, it can be adjusted repeatedly and is easy to use.🔺Application: Used in transistor radios, electronic instruments, and electronic equipment. 1.14 Air Variable Capacitor (CB) 🔺Material: The electrode consists of two sets of metal sheets. One set is the fixed piece, the other is the moving piece, and the air is used as the medium between them. When the rotor is rotated to make it all screw into the stator, its capacitance is the largest, on the contrary, when the rotor is fully screwed out of the stator, the capacitance is the smallest. Air variable capacitors are divided into single-connection and double-connection.🔺Advantages: It is easy to adjust, with stable performance, and not easy to wear.🔺Disadvantage: Bulky.🔺Application: Used in radios, electronic instruments, high-frequency signal generators, and communication electronic equipment. 1.15 Film Variable Capacitors 🔺Material: A plastic film is added between the moving piece and the stator as a medium, and the shell is encapsulated by transparent or translucent plastic, so it is also called a sealed double-connected and four-connected variable capacitor.🔺Advantages: Small size and light weight.🔺Disadvantages: It is easy to wear.🔺Application: Single connection is mainly used in simple radios or electronic instruments; double connection is used in transistor radios and electronic instruments and electronic equipment; quadruple connection is commonly used in AF/FM multi-band radios.   Ⅱ FAQ 1. What are different types of capacitors?Types of CapacitorsCeramic Capacitors.Film Capacitors.Power Film Capacitors.Electrolytic Capacitors.Ceramic capacitors.Film capacitors.Paper capacitors.Electrolytic capacitors. 2. What are the 2 types of capacitor?Capacitors are divided into two mechanical groups: Fixed capacitors with fixed capacitance values and variable capacitors with variable (trimmer) or adjustable (tunable) capacitance values. The most important group is the fixed capacitors. Many got their names from the dielectric. 3. What is the difference between different types of capacitors?The primary difference between the two is that one uses paper while the other uses plastic. Plastic film capacitors hold an advantage over impregnated-paper types in that they have smaller tolerances, high reliability, a long service life, and can continue operating sufficiently while in high temperatures. 4. What devices use capacitor?Capacitors are essential components in a wide range of electronic systems including smart phones, household electric appliances, electric vehicles, and medical devices to name a few. 5. What are capacitors used for?Capacitor, device for storing electrical energy, consisting of two conductors in close proximity and insulated from each other. 6. What is capacitor and its applications?Capacitor is a basic storage device to store electrical charges and release it as it is required by the circuit. Capacitors are widely used in electronic circuits to perform variety of tasks, such as smoothing, filtering, bypassing etc…. One type of capacitor may not be suitable for all applications. 7. Where are capacitors used and why?Capacitors are widely used in electronic circuits for blocking direct current while allowing alternating current to pass. In analog filter networks, they smooth the output of power supplies. 8. How is capacitor used in real life?The most common use for capacitors is energy storage. Additional uses include power conditioning, signal coupling or decoupling, electronic noise filtering, and remote sensing. Because of its varied applications, capacitors are used in a wide range of industries and have become a vital part of everyday life. 9. What are capacitors used for list 5 applications?Applications of capacitors1) Energy storage.2) Pulsed power and weapons.3) Power conditioning.4) Power factor correction.5) Suppression and coupling. 5.1 Signal coupling. 5.2 Decoupling.6) Motor starters. 6.1 Signal processing. 6.2 Tuned circuits.7) Sensing. 7.1 Changing the dielectric.8) Oscillators. 10. What are the advantages of capacitors?Advantages of capacitors include a very high cycle life and charge rates that nearly match discharge rates. Also, supercapacitors can be “floated” for long lengths of time. This means that they will hold their charge (potential energy) for a long period without a large residual decay. 11. Which capacitor is used for high frequency?Mica capacitors have low resistive and inductive components associated with it. Hence, they have high Q factor and because of high Q factor their characteristics are mostly frequency independent, which allows this capacitor to work at high frequency. 12. Where are capacitors used examples?They are used to store energy and then release it when needed.Case 1: Camera flash. A camera flash requires a lot of energy in a short space of time in order to produce a bright enough flash. ...Case 2: Computer emergency shutdown. If a computer loses power it will not be able to shutdown safely. ...Case 3: AC to DC conversion.

Introduction Everyone has heard of FPGA more or less, such as Bitcoin mining, or Microsoft said before that it will use FPGA instead of CPU in the data center. So what exactly is it? Why use it? Compared with CPU, GPU, and ASIC, what are the characteristics of FPGA? FPGA is a chip that can reconfigure circuits and is a hardware reconfigurable architecture. Through programming, users can change its application scenarios at any time, and it can simulate various parallel operations of hardware such as CPU and GPU. By interconnecting with the high-speed interface of the target hardware, the FPGA can complete the low-efficiency part of the target hardware, thereby achieving acceleration at the system level. What Is an FPGA? Catalog Introduction Ⅰ FPGA vs CPU vs GPU vs ASIC Ⅱ Five Advantages of FPGA 2.1 Performance 2.2 Time-to-Market 2.3 Cost 2.4 Stability 2.5 Long-Term Maintenance Ⅲ New Applications of FPGA Ⅳ Development Trend of FPGA Ⅴ FAQ Ⅰ FPGA vs CPU vs GPU vs ASIC The core difference between FPGA and CPU, GPU, ASIC chips, etc. is that the connection and logic layout of the underlying operation unit are not solidified. Users can program the logic unit and switch array through EDA software to configure the function, so as to realize the integration of specific functions.FPGA appears as a semi-custom circuit in the field of application-specific integrated circuits (ASIC), which not only solves the shortcomings of custom circuits, but also improves the limited number of original programmable device gate circuits. Compared with ASIC chips, an important feature of FPGA is its programmable characteristics, that is, the user can specify the FPGA to realize a specific digital circuit through the program. Furthermore, FPGA chips are one of the best choices for small batch systems to improve system integration and reliability. Figure 1. FPGA Basic Structure So why is FPGA so fast? This is all because the computer's CPU(central processing unit) and GPU(graphics processing unit) belong to the von Neumann structure, with instruction decoding and execution, and shared memory. FPGAs, on the other hand, are instruction-free and memory-free architectures that make FPGA chips much more energy-efficient than CPUs or even GPUs. Figure 2. Von Neumann Structure In the von Neumann architecture, since the execution unit (such as the CPU core) may execute any instruction, so an instruction memory, a decoder, an operator of various instructions, and branch and jump processing logic are required. Due to the complex control logic of the instruction stream, it is impossible to have too many independent instruction streams. Therefore, the GPU uses SIMD (single instruction, multiple data) to allow multiple execution units to process different data at the same pace, and the CPU also supports SIMD instruction. The function of each logic unit of the FPGA has been determined during reprogramming, and no instructions are required. Figure 3. Computer CPU If the GPU is used for acceleration, in order to fully utilize the GPU computing, the batch size cannot be too small, and the delay will be on the order of milliseconds. Using FPGA to accelerate, only microsecond-level PCle delay is required. Why is FPGA so much lower latency than GPU? This is basically an architectural difference. FPGAs have both pipeline parallelism and data parallelism, while GPUs have almost only data parallelism (with limited pipeline depth).For example, FPGA chips can change the running hardware design on the chip every few seconds, while chips such as CPU and ASIC are already solidified when they leave the factory and cannot be changed. If ASIC, CPU, GPU, etc. are built buildings, and the routes of rooms, corridors, and stairs in the building have been fixed, while the interior of FPGA is similar to the magic staircase in Hogwarts, which can change the route of room to room at any time. In addition, FPGA does not need to compile the instruction system at the software application level like CPU and GPU. To program FPGA, use hardware description language, and directly compile and burn it into a combination of transistor circuits, that is, directly use transistor circuits to implement user algorithms.The biggest feature of FPGA is its flexibility. It can realize any digital circuit you want and can customize various circuits. Reduce the shackles of special chips, truly tailor-made for your own products, you can flexibly change the design during the design process, and have field programmability, so it is especially suitable for applications that require continuous changes in physical operation logic, such as AI algorithm optimization, data center applications, etc. Architecture Throughput（int ops） Delay Flexibility CPU ~1T N/A Very High GPU ~10T ~1ms High FPGA(Stratix V) ~1T ~1us High FPGA(Stratix 10) ~10T ~1us High ASIC ~10T ~1us Low The FPGA is set up by the RAM stored on the chip to reset its working state, so the on-chip RAM needs to be programmed when working. Users can use different programming methods according to different configuration modes, which can be said to be very flexible and convenient. The FPGA has the following configuration modes:🔺Parallel Mode: Parallel PROM, Flash configures FPGA.🔺Master-Slave Mode: One PROM configures multiple FPGAs.🔺Serial Mode: Serial PROM configures FPGA.🔺Peripheral Mode: The FPGA is used as a peripheral of the microprocessor and programmed by the microprocessor. Computational performance compared with CPU: For example, Stratix series FPGAs perform integer multiplication operations, and their performance is equivalent to that of a 20-core CPU, and for floating-point multiplication operations, their performance is equivalent to an 8-core CPU.Computational performance compared with GPU: FPGA performs integer multiplication and floating-point multiplication operations. There is an order of magnitude difference in performance compared to GPU. The computing performance of GPU can be approached by configuring multipliers and floating-point operation components. Figure 4. CPU and GPU Architecture Diagram The core advantage of FPGA for performing computation-intensive tasks: tasks such as search engine sorting and image processing have strict requirements on the return time limit of results, and it is necessary to reduce the delay of computing steps. Under the traditional GPU acceleration scheme, the data packet size is large, and the delay can reach the millisecond level. Under the FPGA acceleration scheme, the PCIe latency can be reduced to the microsecond level. Driven by long-term technology, the data transmission delay between CPU and FPGA can be reduced to less than 100 nanoseconds.The FPGA can build the same number of pipelines (pipeline parallel structure) for the number of data packet steps, and the data packets can be output immediately after being processed by multiple pipelines. The GPU data parallel mode relies on different data units to process different data packets, and the data units need to be input and output consistently. For stream computing tasks, the FPGA pipeline parallel structure has a natural advantage in latency. FPGA is used to process communication-intensive tasks and is not limited by network cards. It outperforms CPU solutions in terms of packet throughput and delay, and has strong delay stability. Therefore, FPGAs have obvious advantages over CPUs when performing large data processing tasks with high repetition rates.By programming the FPGA, the user can change the internal connection structure of the chip at any time to realize any logic function. Especially in industries with immature technical standards or rapid development and change, FPGA can effectively help enterprises reduce investment risks and sunk costs, and is a functional and economical choice. Figure 5. Computer GPU With the evolution of intelligent market demand, highly customized chips (ASIC SoC) have led to a sharp increase in market risks due to the large scale of non-repetitive investment and long R&D cycle. Relatively speaking, FPGA has advantages in the field of parallel computing tasks, and can replace some ASICs in the field of high performance and multi-channel. The demand for multi-channel computing tasks in the field of artificial intelligence (AI) drives the evolution of FPGA technology to the mainstream. Figure 6. ASIC SoC Ⅱ Five Advantages of FPGA 2.1 Performance Taking advantage of hardware parallelism, FPGAs break the sequential execution model and complete more processing tasks per clock cycle, surpassing the computing power of digital signal processors (DSPs). BDTI(Big Data Test Infrastructure), a well-known analysis and benchmarking company, has published benchmarks that show that in some applications, FPGAs can handle many times more processing power per dollar than DSP solutions. Controlling input and output (I/O) at the hardware level provides faster response times and specialized functionality to meet application needs. 2.2 Time-to-Market Despite increasing time-to-market constraints, FPGA technology offers flexibility and the ability to rapidly prototype. Users can test an idea or concept and complete verification in hardware without going through the lengthy manufacturing process of custom ASIC design. This allows users to make incremental modifications and iterate FPGA designs in hours, saving weeks. Commercial off-the-shelf (COTS) hardware provides different types of I/O connected to user-programmable FPGA chips. The increasing popularity of high-level software tools reduces the learning curve and abstraction layers, and often provides useful IP cores (pre-built functions) for advanced control and signal processing. 2.3 Cost The non-recurring engineering (NRE) cost of custom ASIC design far exceeds the cost of FPGA-based hardware solutions. The huge initial investment in ASIC design shows that OEMs need to ship thousands of chips each year, but more end users need custom hardware capabilities that enable the development of tens to hundreds of systems. The nature of programmable chips means that users can save on manufacturing costs as well as long lead times for assembly. System requirements change from time to time, but the cost of changing the FPGA design is negligible compared to ASCI's huge expense. 2.4 Stability Software tools provide the programming environment, and FPGA circuits are the real "hard" implementation of programming. Processor-based systems often contain multiple layers of abstraction that can schedule tasks and share resources among multiple processes. The driver layer controls hardware resources, while the operating system manages memory and processor bandwidth. For any given processor core, only one instruction can be executed at a time, and processor-based systems face the risk of tightly time-bound tasks taking over each other at all times. FPGAs, on the other hand, do not use an operating system, and have true parallel execution and deterministic hardware that focuses on each task, reducing the chance of stability issues. 2.5 Long-Term Maintenance As mentioned above, FPGA chips are field-upgradable without the time and expense involved in redesigning ASICs. For example, digital communication protocols contain specifications that can change over time, and ASIC-based interfaces can create maintenance and forward compatibility difficulties. Reconfigurable FPGA chips can accommodate future modifications. As a product or system matures, users can enhance functionality without spending time redesigning hardware or modifying board layouts.   Ⅲ New Applications of FPGA At present, the FPGAs mainly produced by Xilinx and Altera with the highest market share, which are all based on SRAM technology, and need to be connected to an external memory to save the program when in use. When powered on, the FPGA reads the data in the external memory into the on-chip RAM, and after completing the configuration, it enters the working state. When power off, the FPGA returns to a white chip, and the internal logic disappears. In this way, the FPGA can not only be used repeatedly, but also does not require a special programmer, but only a general EPROM and PROM programmer. So Actel, QuickLogic and other companies also provide FPGAs with anti-fuse technology, which can only be downloaded once. They have the advantages of anti-radiation, high & low temperature resistance, low power consumption and fast speed. They are widely used in military and aerospace fields. FPGA cannot be erased and written repeatedly, which is troublesome and expensive in the early stage of development. Lattice is the inventor of ISP technology, which has certain characteristics in small-scale PLD applications. Early Xilinx products generally did not involve military and aerospace markets, but now a number of products such as Q Pro-R have entered such fields.In the industrial field, FPGA chips are widely used in the industrial field, and are widely used in video processing, image processing, CNC machine tools and other fields to realize signal control and operation acceleration functions. With the development of intelligence and automation technology, the industrial field is gradually shifting from human resources as the core element to intelligent unmanned factories with automation as the core element.Smart electric vehicles will be the mainstream development direction of the automotive industry in the future. At present, the application of FPGA in automotive cameras and sensors is relatively mature. In the artificial intelligence system of automatic/intelligent driving vehicles, the applicability of FPGA will be the most suitable for processing sophisticated ADAS and autonomous driving. Figure 7. FPGA for Auto In the field of automotive electronic system interface and control, FPGA chips are used to control and drive electric vehicle motor control systems, connect various in-vehicle equipment such as driving systems, instrument panels, radar, ultrasonic sensors, etc. control. In the field of video bridging and fusion, FPGA chips can be used to realize functions such as signal bridging of multiple image sensors, 3D surround view video fusion, reversing auxiliary video, and assisted driving video.In the field of communication, the number of 5G base stations has increased, and the FPGA usage of a single base station has increased, driving the increase in FPGA demand. According to estimates, the FPGA consumption of a 5G single base station is expected to increase from 1-3 blocks in the 4G period to 4-5 blocks in the 5G period. Figure 8. RFSoC FPGA Board Target 5G eFPGA technology is superior to traditional FPGA solutions in terms of performance, cost, power consumption, profitability, etc., and can provide flexible solutions for different application scenarios and different market segments. The economic trend of increasing design complexity and falling equipment costs has stimulated the market demand for eFPGA technology.   Ⅳ Development Trend of FPGA First of all, with the commercialization of the new generation of communication technology, the demand for products such as communication base stations, servers, and intelligent terminals will further expand, thereby driving the increase in the market demand for FPGA chips. At the same time, smart cities, smart factories, and consumer electronics pay more attention to the functionality of various smart IoT devices, which will drive the wide application of FPGA chips in smart IoT devices. With the development of the Internet of Vehicles technology, the scale of the use of FPGA chips in the automotive industry will increase day by day to build a more complete Internet of Vehicles and realize smarter autonomous driving functions. Therefore, with the rapid penetration of 5G, the vigorous development of AI and the increasing trend of automotive intelligence, it is expected that the demand for FPGAs in the three fields of communication, AI and automotive electronics will continue to increase in the future, which will also promote The FPGA industry continues to grow.   Ⅴ FAQ 1. What is FPGA and why it is used?The acronym FPGA stands for Field Programmable Gate Array. It is an integrated circuit that can be programmed by a user for a specific use after it has been manufactured. ... These blocks create a physical array of logic gates that can be customized to perform specific computing tasks. 2. Is FPGA faster than GPU?The difference between GPU and FPGA performance is not a static factor, but it does depend on the size of the data set. A study by Sanaullah and Herbordt [7] revealed that FPGA can compute small samples of 3D FFT tens of times faster than GPU. The difference is less clear when the data set gets bigger. 3. Is FPGA faster than CPU?A FPGA can hit the data cell faster and more often than a CPU can do it meaning the FPGA causes more results to occur during an attack. It all goes faster when an FPGA is used. And as a side benefit, no trace of all this is left on the CPU because it's never touched when an FPGA is used. 4. Are FPGAs efficient?Efficiency and Power: FPGAs are well-known for their power efficiency. A research project done by Microsoft on an image classification project showed that Arria 10 FPGA performs almost 10 times better in power consumption. 5. Is FPGA programming hard?FPGA vendors have touted their wares as ideal replacements for DSPs, CPUs, and GPUs – even for all of them in a single device – but they are notoriously difficult for software engineers to program as they are not anything like a conventional processor. 6. What can you do with FPGAs?Uses for FPGAs cover a wide range of areas—from equipment for video and imaging, to circuitry for computer, auto, aerospace, and military applications, in addition to electronics for specialized processing and more. 7. What is the difference between processor and FPGA?Microprocessor vs FPGA: A microprocessor is a simplified CPU or Central Processing Unit. ... An FPGA doesn't have any hardwired logic blocks because that would defeat the field programmable aspect of it. An FPGA is laid out like a net with each junction containing a switch that the user can make or break. 8. What language is used to program FPGA?VerilogTraditionally, FPGAs are programmed using pro-level hardware-description languages such as Verilog or VHDL. 9. How many times can you program an FPGA?There is effectively no limit to the number of times a device can be reconfigured; the configuration is stored in SRAM, which has no write limit. most Fpgas can be passively loaded from a processor, one word at a time. That processor can get the FPGA image from anywhere. 10. What are the advantages of FPGA?FPGA advantagesLong-term availabilityUpdating and adaptation at the customerVery short time-to-marketFast and efficient systemsAcceleration of softwareReal-time applicationsMassively parallel data processing 11. How do you make an FPGA?FPGA design checklistMake sure you have plenty of time to spare.Find a decent computer.If you can afford it, add a big display.Decide which operating system to use.Consider using a virtual machine (VM).Select an FPGA vendor.Pick out a suitable development board.Select an embedded processor to use. 12. What is FPGA for beginners?FPGA stands for Field Programmable Gate Array. As you may already know, FPGA essentially is a huge array of gates that can be programmed and reconfigured any time anywhere. Huge array of gates is an oversimplified description of FPGA. FPGA is indeed much more complex than a simple array of gates. 13. What is FPGA in Verilog?FPGAs are nothing, but reconfigurable logic blocks and interconnects can be programmed by Hardware Description Language like Verilog/ VHDL to perform a specific functionality. 14. Do we need to program the FPGA once powered off?If you have a SRAM-based FPGA, like the Spartan 3, then you have to program it each time it is powered up. The reason for this is that the SRAM which stores the configuration is volatile and loses the programmed configuration after power is switched off. 15. How is FPGA different from microcontroller?One of the main differences between a microcontroller and an FPGA is that an FPGA doesn't have a fixed hardware structure, while a microcontroller does. While FPGAs include fixed logic cells, these, along with the interconnects, can be programmed in parallel by using HDL coding language.