The Kynix Components

This blog provides you with a basic introduction of the STM32F2 Series, including its advantage, CAD resources, manufacturer, etc., to help you quickly understand what STM32F2 Series are.We will be glad to find that this blog can be useful for STM32F Series fans.This is A Video of Introduction to STM32F2 SeriesCatalogSTM32F2 AdvantageSTM32F2 CAD ResourcesSTM32F2 ManufacturerComponent DatasheetFAQSTM32F2 AdvantageThe STM32F2 series Arm® Cortex®-M3 uses ST's advanced 90 nm NVM process technology with an innovative adaptive real-time memory accelerator (ART AcceleratorTM) and multilayer bus matrix. This offers unprecedented price and performance trade-offs.The series is characterized by a high degree of integration combining up to 1 Mbyte of Flash memory and up to 128 Kbytes of SRAM with Ethernet MAC, USB 2.0 HS OTG, camera interface, hardware support for encryption and external memory interface.ST's acceleration technology enables these microcontrollers to achieve up to 150 DMIPS/398 CoreMark at 120 MHz FCPU, which is equivalent to zero wait state execution, while keeping dynamic current consumption at an exceptionally low level of 175 μA/MHz.Devices are available in packages LQFP64, LQFP100, LQFP144, WLCSP66 (< 4 x 4 mm), UFBGA176 and LQFP176.The series consists of two product lines that are fully compatible with pin-to-pin, peripheral and software. The series also provides close pin-to-pin compatibility with other STM32 products.STM32F205/215 – 120 MHz CPU/150 DMIPS, up to 1 Mbyte of Flash with advanced connectivity and encryptionSTM32F207/217 – 120 MHz CPU/150 DMIPS, up to 1 Mbyte of Flash with advanced connectivity and encryption, adding Ethernet MAC and camera interface to the STM32F205/215, and more GPIOs and features on larger packagesSTM32F2 CAD ResourcesSTM32 F2 series IBIS modelsSTM32F2 Boundary Scan Description Language (BSDL) filesSTM32F2 System View DescriptionSTM32F2 ManufacturerSTMicroelectronics is a Swiss-domiciled multinational electronics and semiconductor manufacturer headquartered in Geneva, Switzerland.STMicroelectronics is a world leader in providing the semiconductor solutions that make a positive contribution to people's lives, today and into the future.That’s all for our introduction to STM32F2. If you find this blog useful, please bookmark our website Apogeeweb, we will provide youwith electronic component blogs, industry news, tools, etc. that you are interested in. Stay tuned for our next blog…Component DatasheetSTM32F205xx, STM32F207xx DatasheetSTM32F215xx, STM32F217xx DatasheetFAQWhy is STM32 So Popular?The STM32 series of microcontrollers from ST Microelectronics is a popular, and very large, family of ARM-based 32-bit microcontrollers. ... While the STM32 microcontrollers are quite versatile and highly configurable, it is this very fact that makes them hard to initialize.Where is STM32 Used?There are various types and varieties of STM32 Microcontrollers available and they belong to the ARM-architecture family of Microcontrollers. These microcontrollers are used in a variety of applications, from simple printers to complex circuit boards in vehicles.How Do I Start STM32?Getting started with STM32 step-by-stepStep 1: Pre-requisites: In this part, user must install all required software tools and make sure it has board for further development.Step 2: LED blinking using STM32CubeMx and NUCLEO-L476RG development board.Step 3: UART interface on NUCLEO-L476RG and L475 IoT Node Discovery board. 

This article will introduce you four simple, useful amplifier circuits of TDA2003. TDA2003 is a ST Microelectronics audio amplifier IC with a maximum output power of 10W,  commonly used in stereo amplification in car Radio. The IC can output a maximum current of 3.5A and has very low harmonic and crossover distortion. For further, detailed introduction to TDA2003 please click here to view: TDA2003>>CatalogI. TDA2003 Integrated OTL Power Amplifier Circuit1.1 Component Required1.2 Circuit Introduction1.3 Circuit Installation PrecautionsII. TDA2003 Power Amplifier Circuit ②2.1 Circuit Introduction2.2 Circuit Charateristics2.3 Circuit Installation PrecautionsIII.TDA2003 Power Amplifier Circuit ③IV. TDA2003 Based 10W Audio Power Amplifier CircuitI. TDA2003 Integrated OTL Power Amplifier Circuit1.1 Component RequiredIntegrated block TDA2003: 1Resistors of 1Ω, 2.2Ω, 39Ω, 220Ω: 1 of each 03μF, 0.03μF, 100μF, 470μF, 1000μF capacitors: 1 of each1μF capacitor: 2 pcsSpeaker 8Ω, 0.25W: 14V power supply: 1  1.2 Circuit IntroductionThe circuit uses the TDA2003 integrated block, which is a simple circuit with a wide passband and beautiful sound quality, and can be widely used in various audio and voice amplification circuits.TDA2003 Integrated OTL Power Amplifier Circuit Pin ① of the integrated block is the input, pin ② is connected to external capacitor C2 and external resistor R3, together they constitute an AC negative feedback, to improve the sound quality of the amplifier. C3, R1 is the anti-self-excitation network, C4 is the output coupling capacitor, C6, C7 is the power supply high and low pass filter capacitor, the supply voltage VCC is 14.4V, the quiescent current is 45mA, the resistance of the load RL is 4Ω, and the power is 6W. 1.3 Circuit Installation Precautions1. The order of the pins of TDA2003 must be judged correctly, and soldering errors are not allowed. When soldering electrolytic capacitors C1, C2, C4, C6, be sure to note that the positive and negative polarities of the capacitors cannot be reversed. 2. The voltage of the power supply VCC cannot be too high or too low, it is appropriate to be about 14.4V. 3. After the soldering is completed, you can use the audio output jack of the radio or recorder to connect the earphone to the input pin 1 in the picture. 4. Heat sinks should be installed on the integrated block TDA2003 to prevent damage due to long working hours. II. TDA2003 Power Amplifier Circuit ②2.1 Circuit IntroductionTDA2030 adopts V-shaped 5-pin single in-line plastic package structure. The following figure is another classic power amplifier application circuit diagram of TDA2003. This integrated circuit is widely used in car stereo radio recorders and medium power audio equipment. It has the characteristics of small size, large output power, and low distortion, and it has an internal protection circuit. Italy SGS company, American RCA company, Japan Hitachi company, NEC company, etc. all have similar products produced. Although their internal circuits are slightly different, the positions and functions of the lead pins are the same.TDA2003 Power Amplifier Circuit 22.2 Circuit CharateristicsVery few external componentsLarge output power, Po=18W (RL=4Ω)The use of ultra-small package (TO-220) can increase the assembly density.Minimal boot impact.It contains various protection circuits, so it is safe and reliable to work. The main protection circuits are: short-circuit protection, thermal protection, accidental open circuit of the ground wire, reverse connection of power supply polarity (Vsmax=12V), and load discharge voltage kickback.TDA2030A can output 16W effective power when working at ±19V and 8Ω impedance at a minimum voltage of ±6V and a maximum of ±22V, THD≤0.1%.Undoubtedly, it is very suitable for the power amplification part of computer active speakers or small power amplifier. 2.3 Circuit Installation Precautions 1. TDA2030 has a load discharge voltage kickback protection circuit. If the peak voltage of the power supply voltage is 40V, then an LC filter must be inserted between pin 5 and the power supply to ensure that the pulse train on pin 5 remains within the specified range. 2. Thermal protection: Thermal limit protection has the following advantages, it can easily withstand output overload (even for a long time), or protect it when the ambient temperature exceeds. 3. Compared with ordinary circuits, the heat sink can have a smaller safety factor. If the junction temperature exceeds, it will not damage the device. If this happens, Po= (and Ptot of course) and Io will be reduced. 4. The decoupling of the ground wire and the output must be considered in the design of the printed circuit board, because these circuits have large currents. 5. The heat sink does not need to be insulated during assembly, the lead length should be as short as possible, and the solderingtemperature should not exceed 260°C for 12 seconds. 6. Although TDA2030 requires few components, the selected components must be quality-guaranteed components. III.TDA2003 Power Amplifier Circuit ③ TDA2003 Power Amplifier Circuit 3 In this circuit, pin 1 is the signal input and signal flow; the signal is coupled to the tda2003-1 pin via a 4.7 microfarad capacitor, a volume adjustment potentiometer and a 47 microfarad capacitor, the 2 pin is an RC network, the 3 pin is grounded, and the 4 pin has four outputs. The two components connected in parallel with the speaker are anti-self-excitation. Pin 5 is power supply. Two capacitors filter high frequencies and filter low frequencies. 220 ohms for 2 feet and 4 feet is negative feedback, 47 ohms divided by 220 ohms is the magnification. IV. TDA2003 Based 10W Audio Power Amplifier Circuit TDA2003 Based 10W Audio Power Amplifier Circuit This amplifying circuit can approximate 10 watts of power to 2 ohms and 4 ohms to 4 watts. The maximum power can be obtained with a 16 V DC power supply and a 2 ohm impedance speaker with a current of more than 1A. A power of more than 4 watts can obtain a 12 volt DC power supply and a current of more than 14 ohm impedance. 

AD620 is a low cost, high accuracy instrumentation amplifier that requires only one external resistor to set gains of 1 to 10,000. This blog covers AD620 amplifier pinout, datasheet, equivalent, features, and other information on how to use and where to use this device.CatalogAD620 IntroductionAD620 PinoutAD620 Basic ParametersAD620 FeaturesAD620 ApplicationsWhere to use AD620 amplifier?How to use AD620 amplifier?AD620 PackageAD620 Application CircuitAD620 Working PrincipleAD620 Alternative ModelsAD620 ManufacturerFAQOrdering & QuantityAD620 IntroductionADI’s AD620 comes in 8-lead SOIC and DIP packages and are low-cost, high-accuracy instrumentation amplifiers that, with an external resistor, allow the user to set gains of 1 to 10,000. The small footprint design and low power consumption (only 1.3 mA (maximum) supply current) make it a good fit for portable or remote applications that require a battery. The AD620, with its high accuracy of 40 ppm (maximum) nonlinearity, low offset voltage of 50 µV (maximum), and offset drift of 0.6 µV/°C (maximum), is ideal for use in precision data acquisition systems such as weigh scales and transducer interfaces. Furthermore, the low noise, low input bias current, and low power of the AD620 make it well suited for medical applications such as ECG and noninvasive blood pressure monitors. The low input bias current of 1.0 nA (maximum) is made possible with the use of Superϐeta processing in the input stage. The AD620 works well as a preamplifier due to its low input voltage noise of 9 nV/√Hz at 1 kHz, 0.28 μV p-p in the 0.1 Hz to 10 Hz band, and 0.1 pA/√Hz input current noise. Also, the AD620 is well suited for multiplexed applications with its settling time of 15 μs to 0.01%, and its cost is low enough to enable designs with one in-amp per channel.AD620 PinoutThe datasheet provided above is for your reference, so that you can understand the physical dimensions of all packages in more detail. The configuration of all 8 pins and the function of each pin are as follows: The function of all 8 pins are as follows:Pin NumberPin NameDescription1Gain (Rg)Inverting Gain Terminal connected to a resistor to set gain value2Inverting Input (IN-)The Inverting input pin of the Op-Amp3Non- Inverting Input (IN-)The Non - Inverting Input Pin of Amplifier4Power (-Vs)Negative supply terminal5ReferenceOutput reference input. Normally connected to common6OutputAmplifier output pin7Power (+Vs)Positive supply terminal8Gain (Rg)Non - Inverting Gain Terminal connected to resistor to set gain valueAD620 Basic ParametersParametersAD620AAD620BAD620SGain Range10,00010,00010,000Gain Error G=1 (%) 0.100.020.10Gain Error G=1000 (%)0.70.50.7Input Offset (µV)12550125Input Bias current (nA)2.01.02.0Input Offset Current (nA)1.00.51.0Input Voltage Range (V)+ -1.2+ -1.2+ -1.2Input offset current (nA)20050500Input Impedance Differential Common Mode (GΩ_pF)10II210II210II2Common Mode Rejection Ratio G=1 (dB)909090Common Mode Rejection Ratio G=1000 (dB)130130130Slew Rate (V/µs)1.21.21.2Small Signal -3dB Bandwidth G=1 (kHz)100010001000Small Signal -3dB Bandwidth G=1000 (kHz)121212Settling Time to 0.01% G= 1-100 (µs)151515Settling Time to 0.01% G= 1000 (µs)150150150Input Voltage Noise (nV/ Hz)131313Output Voltage Noise (nV/ Hz)100100100Reference Input Resistance (kΩ)202020Reference Input Current (µA)606060Reference Input Voltage Range (V)+ -1.6+ -1.6+ -1.6Output Short Circuit DurationIndefiniteIndefiniteIndefiniteLead Temperature Range for 10sec soldering (°C)300300300Operating Temperature Range (°C)-40 to +85-40 to +85-55 to +125AD620 FeaturesEASY TO USE　　Gain Set with One External Resistor　　(Gain Range 1 to 10,000)　　Wide Power Supply Range (±2.3 V to ±18 V)　　Higher Performance than Three　　Op Amp IA Designs　　Available in 8-Lead DIP and SOIC Packaging　　Low Power, 1.3 mA max SupplyLOW NOISE　　9 nV/√Hz, @ 1 kHz, Input Voltage Noise　　0.28 µV p-p Noise (0.1 Hz to 10 Hz)EXCELLENT DC PERFORMANCE (B GRADE)　　50 µV max, Input Offset Voltage　　0.6 µV/°C max, Input Offset Drift　　1.0 nA max, Input Bias Current　　100 dB min Common-Mode　　Rejection Ratio (G = 10)EXCELLENT AC SPECIFICATIONS　　120 kHz Bandwidth (G = 100)　　15 µs Settling Time to 0.01%AD620 ApplicationsWeigh scalesECG and medical instrumentationTransducer interfaceData acquisition systemsIndustrial process controlsBattery-powered and portable equipmentWhere to use AD620 amplifier?The AD620, with its high accuracy of 40 ppm maximum nonlinearity, low offset voltage of 50 μV max, and offset drift of 0.6 μV/°C max, is ideal for use in precision data acquisition systems, such as weigh scales and transducer interfaces. Furthermore, the low noise, low input bias current, and low power of the AD620 make it well suited for medical applications, such as ECG and non-invasive blood pressure monitors.How to use AD620 amplifier?The AD620 only requires a resistor to set its gain value and can therefore be easily set up. The most basic commonly used circuit for AD620 is shown below.The IC is powered by pin 7 and pin 4 is connected to the ground. Here I used a single supply of +5V. The non-inverting pin (pin 2) and the inverting pin (pin 3) are connected to the signal to be amplified or compared on the basis of the Op-Amp application. The reference pin (pin 5) is normally grounded along with pin 4, the reference pin is used to direct the output to the voltage when the difference voltage between the inverter and the non-inverter pin is 0V. The Gain of the Op-Amp can be set simply by connecting the correct resistance value to the pin +Rg (pin 8) and the pin –Rg (pin 1). Here I have connected a resistor with a value of 500, which will set the Op-Amp to a gain value of 100. The formulas used to calculate the gain value from R have been given below.G = (49.4 k/RG) + 1AD620 PackageAD620 Application CircuitAD620 Working PrincipleThe AD620 is a monolithic instrumentation amplifier based on a modification of the classic three op amp approach. Absolute value trimming allows the user to program gain accurately (to 0.15% at G = 100) with only one resistor. Monolithic construction and laser wafer trimming allow the tight matching and tracking of circuit components, thus ensuring the high level of performance inherent in this circuit. The input transistors Q1 and Q2 provide a single differentialpair bipolar input for high precision (Figure 36), yet offer 10× lower input bias current thanks to Superϐeta processing. Feedback through the Q1-A1-R1 loop and the Q2-A2-R2 loop maintains constant collector current of the input devices Q1 and Q2, thereby impressing the input voltage across the external gain setting resistor RG. This creates a differential gain from the inputs to the A1/A2 outputs given by G = (R1 + R2)/RG + 1. The unity-gain subtractor, A3, removes any common-mode signal, yielding a single-ended output referred to the REF pin potential. The value of RG also determines the transconductance of the preamp stage. As RG is reduced for larger gains, the transconductance increases asymptotically to that of the input transistors. This has three important advantages: (a) Open-loop gain is boosted for increasing programmed gain, thus reducing gain related errors. (b) The gain-bandwidth product (determined by C1 and C2 and the preamp transconductance) increases with programmed gain, thus optimizing frequency response. (c) The input voltage noise is reduced to a value of 9 nV/√Hz, determined mainly by the collector current and base resistance of the input devices. The internal gain resistors, R1 and R2, are trimmed to an absolute value of 24.7 kΩ, allowing the gain to be programmed accurately with a single external resistor. The gain equation is then AD620 Alternative ModelsAD8422Higher BW at 1/3 the power, with RRO and OVP (same pinout as AD8221)AD620 ManufacturerAnalog Devices (NASDAQ: ADI) is a world leader in the design, manufacture, and marketing of a broad portfolio of high performance analog, mixed-signal, and digital signal processing (DSP) integrated circuits (ICs) used in virtually all types of electronic equipment. Since established in 1965, ADI have focused on solving the engineering challenges associated with signal processing in electronic equipment. ADI currently produce a wide range of innovative products—including data converters, amplifiers and linear products, radio frequency (RF) ICs, power management products, sensors based on microelectromechanical systems (MEMS) technology and other sensors, and processing products, including DSP and other processors—that are designed to meet the needs of our broad base of customers.Component DatasheetAD620 DatasheetFAQWhat is AD620?AD620 is a low-cost, high-precision instrumentation amplifier. It only requires an external resistor to set the gain. The gain range is 1 to 10,000.Can I change AD620 to AD623 when making MCU products?Both AD620 and AD623 are single instrumentation amplifiers, and the pin arrangement is exactly the same.The main difference is: AD620 must use positive and negative power supplies, AD623 can be a positive and negative power supply or a single power supply.If the original board is AD620, you can replace it with 623; if the original board is AD623, you may not be able to replace it with 620 (it depends on whether the power supply of the original board circuit is dual power supply or single power supply).After replacing AD620 and AD623 in single-chip products, the program can work normally without modification.What is the difference between AD620BR and AD620AN?Their packages are different.What is the output resistance of AD620? How to adjust it?AD620 is a kind of low power consumption instrument amplifier, its output resistance is about 10K, this is the inherent characteristic of this chip, generally it is difficult to adjust.If you have requirements for output resistance, you can generally use an external circuit to solve it.Is AD620 a positive phase amplification or a reverse phase amplification?AD620 is an instrument amplifier, the output voltage is [(Vin+)-(Vin-)]*gain.If the desired signal is (Vin+)-(Vin-), the gain is positive, which is equivalent to positive amplification.Conversely, if the desired signal is (Vin-)-(Vin+), the gain is equivalent to negative, which is equivalent to reverse amplification.What is an instrumentation amplifier?Instrumentation amplifier, an improvement of the differential amplifier, has an input buffer, does not require input impedance matching, so that the amplifier is suitable for measurement and electronic instruments

 CR2032 batteries and DL2032 batteries that are round, flat, and look like small silver buttons seem to look the same. Since they all look the same, can they be used universally?  This article will answer your questions and show you theirs similarities and differences, as well as the interchangeability. CatalogWhat is a DL2032 Battery?What is a CR2032 Battery?DL2032 vs CR2032 Spec ComparisonDL vs CR BatteriesDL2032 vs CR2032 InterchangeabilityBattery Safety IssuesBattery DL2032 vs CR2032 FAQ What is a DL2032 Battery? DL2032 Battery Designed for enhanced battery life in compatible 3V devices, the Duracell DL2032-2 3V Lithium Battery delivers ample power when you need it most. These Category 2032 batteries are suitable for use with small electronic devices including calculators, wristwatches, medical devices, appliances, and more. Designed for use with crucial electronics, this battery is trusted by countless individuals to deliver reliable power for an extended period of time. Each pack includes two batteries. Works in: Watches, computer motherboards, calculators, PDAs, electronic organizers, garage door openers, toys, games, door chimes, pet collars, LED lights, sporting goods, pedometers, calorie counters, stopwatches and medical devices What is a CR2032 Battery? CR2032 Battery The CR2032 coin cell battery possesses high energy density and has ability to perform consistently in extreme temperatures (ranging from 85C to -30C) environments compared to other batteries. It uses manganese dioxide lithium chemistry with a voltage of 3 volts and 225 mAh typical in capacity. It has a height of 3.2 mm and a diameter of 20 mm. This battery also discharges evenly, and has excellent leakage resistance characteristics. CR2032 batteries have the proven ability to provide a stable supply of power for a long period of time, much longer than a regular dry battery. DL2032 vs CR2032 Spec Comparison DL2032 CR2032Battery Size: 20322032Brand: DuracellPanasonic Chemistry: Lithium/Manganese Dioxide (Single Use)Lithium Manganese DioxideVoltage: 3V3VCapacity: 225 mAh225mAhDiameter: 0.8" (20mm)0.8" (20mm)Height: 0.13" (3.2mm)0.13" (3.2mm)Weight:4.5g3.1gMinimum Operating Temperature: - 20°C  - 30°CMaximum Operating Temperature: +60°C +60°C Continuous Drain Current0.19 mA0.19 mA DL vs CR BatteriesWhen it comes to unusual batteries like the coin type batteries, it is a bit more important to get the exact type that you are looking for to ensure that it is the correct fit and voltage and avoid having to buy the battery again. This is the case when it comes to CR batteries like the CR2032 and DL2032. The main difference between CR and DL batteries is just the maker. CR is basically a generic designation just like AA and AAA. It is used by almost all battery makers. On the other hand, the DL designation is used by the battery maker Duracell. The probable rationale behind changing from the generic designation to a unique one is to differentiate their product from what is commonly available. Duracell may want to differentiate their product because it has a higher capacity and they want that reputation to spread. Not really very easy when the batteries at this category are used in low power devices and would typically last for months if not years. What this change actually does is raise some confusion as consumers would typically look for an exact match to the battery that they have. Actually, the DL and CR batteries are interchangeable as long as the numbers that follow are the same. Given the example above, a DL2032 battery can be used to replace a CR2032 battery and vice versa. The numbers stamped in the battery are not random; they are actually a description of the physical dimensions of the battery. The last two digits pertains to the thickness of the battery while the first two (or first for batteries that only have three digits) pertain to the diameter. So, for the 2032, it basically says that the battery has a 20mm diameter and is 3.2mm thick. DL2032 vs CR2032 InterchangeabilityWhen it comes to unusual batteries like the coin type batteries, it is a bit more important to get the exact type that you are looking for to ensure that it is the correct fit and voltage and avoid having to buy the battery again. This is the case when it comes to CR batteries like the CR2032 and DL2032. The main difference between CR and DL batteries is just the maker. CR is basically a generic designation just like AA and AAA. It is used by almost all battery makers. On the other hand, the DL designation is used by the battery maker Duracell. DL2032 Battery The fact that the battery CR2032 is made by a different manufacturer can lead to some subtle differences, such as the capacity of Energizer CR2032 is 235 mAh, but the capacity of Panasonic CR2032 is 225mAh.  CR2032 Battery Battery Safety IssuesCR2032 Batteries don't contain mercury, cadmium, and similar toxic metals, but nonetheless, when they are discharged, they should be recycled properly. Also, CR2032 batteries are small, shiny objects that can attract kids and pets - although they are not the smallest button/coin-cells on the marketplace, they can get swallowed. That is why CR2032 and similar batteries are packaged in 'kids safe packages. But, if they get swallowed, they can cause chemical burns caused by electrolysis, which can be very dangerous, even deadly. If CR2032 or any other similar battery gets swallowed, immediately contact the nearest emergency center, explain to them what happened, and act according to their instructions. Battery DL2032 vs CR2032 FAQ① Are CR2032 and DL2032 interchangeable?Actually, the DL and CR batteries are interchangeable as long as the numbers that follow are the same. Given the example above, a DL2032 battery can be used to replace a CR2032 battery and vice versa. So, for the 2032, it basically says that the battery has a 20mm diameter and is 3.2mm thick. ② Is Duracell DL2032 rechargeable?Lithium CR2032, DL2032, BR2032, ML2032, LiR2032, LR2032 Batteries – Equivalents and Replacements. Lithium CR2032 is a very popular non-rechargeable lithium 3.0 V battery, often used in watches, calculators, medical equipment, remote controls, and other smaller electronic devices. ③ Are CR2025 and CR2032 the same?The obvious difference between the two battery types would be thickness. The CR2032 is 3.2mm thick while the CR2025 is 2.5mm thick. Because the CR2032 is 0.7mm thicker than the CR2025, it has a higher capacity (mAh) to deliver current to the load. ④ What does CR stand for on batteries?CR is the generic designation that is used by the entire batteries maker but lithium batteries are also having chromium. All the batteries who have this chemical substance in their batteries they can use this abbreviation CR. On the other DL is the short abbreviation of the battery making company Duracell. ⑤ What are 3 volt lithium batteries used for?Digital Cameras. Most forms of digital cameras employ either a single-use 3V lithium battery or their rechargeable brethren.Lithium batteries have a notoriously long life, making them ideal for use in emergency flashlights.TV Remotes and Other Electronics.

In this blog, Apogeeweb has prepared 8 simple 2N3904 circuits for electronics enthusiasts. These circuit diagrams are basically beginner-friendly types. Hope these circuit diagrams are helpful to you.Catalog2N3904 CircuitsComponent DatasheetFAQ2N3904 CircuitCircuit 1: Thermostat controller composed of LM75 intelligent temperature sensor and 2N3904 transisitorCircuit 2Circuit 3Circuit 4Circuit 5Circuit 6: 2N3904 Sample Circuit-AmplifierCircuit 7: How to design a 13.56mhz sine wave power amplifier circuit with 2N3904Circuit 8: The non-inverting circuit uses a pair of complementary NPN type (2N3904) and PNP type (2N3906) transistorsComponent Datasheet2N3904 DatasheetFAQWhat is a 2N3904 Transistor?The 2N3904 is a common NPN bipolar junction transistor used for general-purpose low-power amplifying or switching applications. It is designed for low current and power, medium voltage, and can operate at moderately high speeds.How Does a 2N3904 Transistor Work?2N3904 is a NPN transistor hence the collector and emitter will be left open (Reverse biased) when the base pin is held at ground and will be closed (Forward biased) when a signal is provided to base pin. 2N3904 has a gain value of 300; this value determines the amplification capacity of the transistor.What is PNP NPN?PNP sensors produce a positive output to your industrial controls input, while NPN sensors produce a negative signal during an “on” state. ... NPN, or “sinking” output sensors, work in the opposite way, sinking ground voltage to an input when it's on.Whats is A Transistor?A transistor is a semiconductor device used to amplify or switch electronic signals and electrical power. It is composed of semiconductor material usually with at least three terminals for connection to an external circuit.What is the Gain of a Transistor?The current gain for the common-base configuration is defined as the change in collector current divided by the change in emitter current when the base-to-collector voltage is constant. Typical common-base current gain in a well-designed bipolar transistor is very close to unity.

This article first introduced the three commonly used stable output voltage circuits of UC3842, analyzed their respective advantages and disadvantages, and designed a new voltage feedback circuit on this basis. Experiments prove that this new circuit has a good voltage stabilizing effect.CatalogI. Common Voltage Feedback Circuits1.1 Direct voltage division of the output voltage as the input of the error amplifier1.2 Auxiliary power supply output voltage division as the input of the error amplifier1.3 Change the input error voltage of the error amplifier using linear optocouplerII. Experiments and Results2.1 Change the gain of error amplifier by using linear optocoupler2.2 Experimental resultsIII. ConclusionI. Common Voltage Feedback CircuitsGenerally, the PWM type switching power supply uses sampling of the output voltage as the feedback voltage of the PWM controller. After the feedback voltage is passed through the error amplifier inside the PWM controller, the duty cycle of the switching signal is adjusted to achieve the stability of the output voltage. But different voltage feedback circuits have different output voltage stability accuracy. The internal circuit diagram of UC3842 is shown as in Figure 1.UC3842 Internal Circuit 1.1 Direct voltage division of the output voltage as the input of the error amplifierAs shown in Figure 2, the output voltage Vo is divided by R2 and R4 and then used as a sampling signal and input to the UC3842 pin 2 (the reverse input of the error amplifier). The forward input of the error amplifier is connected to the reference voltage of 2.5V inside the UC3842. When the sampling voltage is less than 2.5V, the voltage difference between the forward and reverse outputs of the error amplifier is amplified by the amplifier to adjust the output voltage, making the duty cycle of the output signal of the UC3842 larger, the output voltage rises, and finally the output voltage is stabilized at the set voltage value.R3 and C1 are connected in parallel to form a current-type feedback. The advantage of this circuit is that the sampling circuit is simple, but the disadvantage is that the input voltage and output voltage must share the same ground and cannot be electrically isolated. This is easy to cause difficulty in power supply wiring, and the power supply works in a high-frequency switching state, which is easy to cause electromagnetic interference, which will inevitably bring difficulties in circuit design, so this method is rarely used.Figure 2 Sampling diagram for direct voltage division of output voltage 1.2 Auxiliary power supply output voltage division as the input of the error amplifierAs shown in Figure 3, when the output voltage rises, the induced voltage generated on the auxiliary winding of the single-ended flyback transformer T also rises, and the voltage is rectified, filtered and regulated by D2, D3, C15, C14, C13 and R15 to obtain a DC voltage to power the UC3842. At the same time, the voltage is divided by R2 and R4 as a sampling voltage and sent to the UC3842's pin 2. After comparing with the reference voltage, it is amplified by the error amplifier, so that the duty cycle of pin 6 output pulse becomes smaller and the output voltage drops to achieve the purpose of voltage regulation. Similarly, when the output voltage decreases, the duty cycle of the output pulse of pin 6 becomes larger and the output voltage rises, finally stabilizing the output voltage at the set value.Figure 3 Sampling Diagram for auxiliary power supply division of output voltage The advantage of this circuit is that the sampling circuit is simple, and there is no electrical path between the secondary winding, the primary winding and the auxiliary winding, which is easy to wire.  The disadvantage is that the sampling voltage is not obtained directly from the secondary winding, and the voltage stabilization effect is not that positive. It was found in the experiment that the voltage stabilization basically cannot be achieved when the load of the power supply varies greatly. The circuit is suitable for the case of a fixed load. 1.3 Change the input error voltage of the error amplifier using linear optocouplerAs shown in the figure 4, the voltage sampling circuit of the switching power supply has two circuits: one is the voltage of the auxiliary winding through D1, D2, C1, C2, C3, R9 rectification, filtering and voltage regulation to obtain 16V DC voltage to the UC3842 power supply, in addition, the voltage through R2 and R4 voltage division to obtain a sampling voltage, the sampling voltage mainly reflects the change of the DC bus voltage. The other is the photocoupler, three-terminal adjustable regulator Z and R4, R5, R6, R7, R8 voltage sampling circuit, the road voltage reflects the change in the output voltage; when the output voltage rises, the reference voltage of the input Z also rises after the resistor R7 and R8 divides the voltage, the regulator voltage value of the regulator rises, the current flowing through the light-emitting diode in the photocoupler decreases, the current flowing through the phototransistor in the photocoupler also correspondingly reduced, the error amplifier input feedback voltage is reduced, resulting in the UC3842 pin 6 output drive signal duty cycle becomes smaller, so the output voltage drops, to achieve the purpose of voltage regulation.Figure 4 Auxiliary power sampling and optocoupler sampling synthesis Since the circuit uses an opto-coupler, it achieves the isolation of output and input, the isolation of weak and strong power, reducing electromagnetic interference, thus its anti-interference ability is improved, and it is to the output voltage sampling, with good voltage regulation performance. The disadvantage of the circuit is the increase in external components, which increases the difficulty of wiring and adds the cost of the power supply. II. Experiments and Results2.1 Change the gain of error amplifier by using linear optocoupler As shown in Figure 5, the voltage sampling and feedback circuit consists of R2, R5, R6, R7, R8, C1, opto-coupler, and three-terminal adjustable regulator Z. When the output voltage rises, the output voltage is divided by R7 and R8 to obtain the sampling voltage (i.e., Z's reference voltage) also rises, Z's regulator value also rises, the current flowing through the light-emitting diode in the photocoupler decreases, resulting in a reduction in the current flowing through the phototransistor. This is equivalent to C1 parallel variable resistor resistance value becomes large (the equivalent resistance value by the flow of light-emitting diode current control), the gain of the error amplifier becomes large, resulting in the UC3842 pin 6 output of the drive signal duty cycle becomes small, the output voltage drops to achieve the purpose of voltage regulation. When the output voltage decreases, the gain of the error amplifier becomes smaller and the duty cycle of the output switching signal becomes larger, which eventually stabilizes the output voltage at the set value. Because the voltage feedback input pin 2 of UC3842 is grounded, so the input error of the error amplifier is always fixed, and what changes is the gain of the error amplifier (the phototransistor in the linear optocoupler can be regarded as a variable resistor), and its equivalent circuit diagram is shown in Figure 6.Figure 5 Varying the gain of the error amplifier using an optocouplerFigure 6 Equivalent circuit for changing the gain of the error amplifier The circuit changes the output of the error amplifier by adjusting the gain of the error amplifier instead of adjusting the input error of the error amplifier, thus changing the duty cycle of the switching signal. This topology not only has fewer external components, but also employs a three-terminal adjustable regulator in the voltage sampling circuit, making the output voltage essentially unchanged when the load changes significantly. The experiment proves that the circuit has a very good voltage regulation effect compared with the above three feedback circuits. 2.2 Experimental resultsThis new voltage feedback circuit using a linear optocoupler to change the gain of the error amplifier is used in a 48V/12V single-ended flyback DC/DC switching power supply (maximum output current of 5A), which shows that the output voltage of the power supply is stable and has a strong load carrying capability. Figure 7(a)-(h) gives the output voltage and drive waveforms when the load is 100Ω, 25Ω, 10Ω, and 3Ω, respectively. From the waveforms, it can be seen that when the load current gradually increases, the duty cycle of the drive signal increases accordingly, but the output voltage is always stable at 12.16V.Figure 7 Output voltage and drive waveform at different loads III. ConclusionIn the single-ended isolated PWM power supply, the current-mode pulse width modulator UC3842 has a wide range of applications. This article summarizes the voltage feedback circuit design that uses a linear optocoupler to change the gain of the UC3842 error amplifier. And it is proved by experiments that the new voltage feedback circuit has high voltage regulation accuracy and strong load adaptability.