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This paper introduces a switching power supply with the half-bridge circuit. Its input voltage is AC 220V ±20V, the output voltage is DC 4V ~16V, the maximum current is 40A, and the working frequency is 50kHz. And its design idea, working principle, and characteristics of the power supply are introduced emphatically. 12V 10A switching power supply (with schematic and explanation)   Catalog   I. Introduction II. Main Technical Indicators III. Main Functions Description 3.1 AC EMI Filter and Rectifier Filter Circuit 3.2 Half-bridge Power Converter 3.3 Design of Power Transformer 3.4 Design of Auxiliary Power Supply 3.5 Drive Circuit 3.6 Fan Wind Speed Control Circuit 3.7 PWM Control Circuit 3.8 Current Fold back Circuit FAQ       I. Introduction Power supplies with the voltage of 5~15V and current at 5~40A are most commonly used in scientific research, production, experiments and other applications. The maximum current of the general experimental power supply is only 5A or 10A, For this purpose, a switching power supply with continuously adjustable voltage at 4V~16V and maximum output current of 40A has been developed. It adopts half-bridge circuit, with power MOS transistor as switching device and the switching frequency is 50kHz. Light weight, small volume and low cost are advantages of it.   II. Main Technical Indicators   1) Output Voltage: AC 220V±20％  2) Input Voltage: DC 4～16V(adjustable) 3) Output Current: 0~40A 4) Output Voltage Adjustment Rate: ≤1％ 5) Ripple Voltage Up: p≤50mV 6) Current / Voltage Display Function and Fault Alarm Indication   Basic Working Principles and Schematic Diagrams The schematic block diagram of the power supply is shown in Fig.1. After 220V AC voltage is filtered by EMI and rectifier, about 300V DC voltage is added to the half-bridge converter to drive the power MOS tube with the dual pulse signal generated by the pulse width modulation(PWM) circuit. The quasi-square-wave voltage is gained by coupling and isolating the power transformer, and a stable DC output voltage can be obtained by rectifying filter feedback control. Fig. 1 Working Block Diagram of Integral Power Supply   III. Main Functions Description   3.1 AC EMI Filter and Rectifier Filter Circuit Fig.2 AC EMI Filter and Input Rectifier Filter Circuit The power line of the electronic equipment is an important way of electromagnetic interference (EMI) to get into or out of the electronic equipment, but installing the power line filter at the entrance of the power line of the equipment can effectively cut off the transmission path of EMI. And it composed of IEC plug power filter and PCB power filter.   The main purpose of the IEC plug power filter is to prevent the interference from the power grid from entering the power supply box, and for PCB power filter the purpose is to suppress the high frequency noise generated when the power switch is switched. Bridge rectifier circuit is used when AC input voltage is 220V, if JTI jumper is short-connected, then 110V is suitable.   Because the input voltage is high and the capacitor capacity is large, the surge impulse current will be produced at the moment when the power network is switched on, and the general surge current value is tens of times that of the steady current.   This may result in the damage of rectifier bridge and input fuse, or the saturation damage to power devices of high frequency transformer cores, and the reduction of the service life of high voltage electrolytic capacitors, etc. So the input soft start circuit composed of resistance R1 and relay K1 is added in front of rectifier bridge to avoid those damages.   3.2 Half-bridge Power Converter The power supply uses half-bridge converter circuit, as shown in Fig.3, its operating frequency is 50kHz, the main parts on the primary side are power transistors: Q4 and Q5, and capacitors: C34 and C35. Q4 and Q5 alternately conduct and cutoff, A positive and negative square wave pulse voltage of U1/2 is generated through the primary winding N1 of a high frequency transformer. The energy is transferred from transformer to the output, and Q4 and Q5 use IRFP460 power MOS transistor. Fig.3 Switching Power Supply Schematic   3.3  Design of Power Transformer   1) Setting of the Working Frequency The working frequency has a great influence on the volume, weight and circuit characteristics of the power supply. The output filter inductance and capacitance volume decrease with high working frequency, but the switching loss increases, the heat quantity increases and the radiator volume increases. Therefore, according to the factors such as components and cost performance, optimizing the operating frequency of power supply, the formula is fs=50kHz, T=1/fs=1/50kHz=20μs.   2)Core Selection ①Selecting the EE type ferrite core made of R2KB ferrite material, has many advantages, such as versatility, large lead space, convenient wiring operation, economics, and so on. ②Determination of Working Magnetic Induction Intensity: Bm The saturation magnetic induction intensity of R2KB soft magnetic ferrite material is Bs=0.47T, considering that Bs will decrease at high temperature, and in order to prevent the saturation of high-frequency transformer at the moment of closing,  selecting Bm=1 / 3Bs= 0.15T ③Calculation and Determination of Core Type The geometric cross-sectional area S and the window area Q of the magnetic core have a certain functional relationship with the output power Po. For half-bridge converters, when the pulse waveform is an approximately square wave, having SQ= (1) η—Efficiency j—Current density, generally 300~500A/cm2 kc—Fill factor of magnetic core, ferrite core kc=1 Ku—Filling coefficient of copper, related to the wire diameter, winding process, winding number, and so on, is generally about 0.1~0.5. The units of each parameter: Po—W，S—cm2, Q—cm2, Bm—T, fs—Hz, j—A/cm2. The values each parameter:  Po=640W，Ku=0.3,j=300A/cm2,η=0.8,Bm=0.15T, plugging these into formula(1) to get SQ=4.558cm4. From the manufacturer manual of EE55 magnetic core: S=3.54cm2, Q=3.1042cm2, calculating SQ=10.9cm4, the SQ value of EE55 magnetic core is larger than the calculated value. EE55 magnetic core is the option.   3) Calculating Turns of Primary and Secondary Side Windings Calculate the primary number turns of windings according to the lowest input voltage and the full load(the duty ratio is maximum). It is known that the DC input voltage of Umin=176V after rectifying and filtering is Udmin=1.2 × 176 = 211.2V. For the half-bridge circuit, the voltage applied on the primary winding of the power transformer is equal to half of the input voltage, that is Upmin=Udmin/2=105.6V, assuming Dmax=0.9(the maximum duty ratio), getting tonmax= T × Dmax= 20 × 0.9 μs.   Design of an Output Voltage 4~16V Switching Power Supply   Fig.4 Schematic Diagram of Auxiliary Power Supply Upmin×tonmax×104=105.6×9.0×10－6×104, plugging into formula N1=8.9 turns,  the maximum output voltage is Uomax=16V when calculating secondary turns; the secondary circuit uses full wave rectifier, Us as the inductive voltage on the secondary winding and Uo as the output voltage and Uf as the rectifier diode voltage drop, taking 1 V as the voltage drop, Uz is filter inductor equal circuit voltage drop taking 0.3V, getting Us=19.22V×N2=N1×8.9=1.8 turns; For the convenience of winding the transformer, if the secondary winding is 2 turns, then the primary winding will be corrected to N1=N2=10 turns.   4) Selected Wire Diameter When selecting the wire diameter of the winding, the skin effect of the wire should be considered. It is generally required that the wire diameter be less than two times the penetration depth, and the penetration depth Δ is determined by formula (2), Δ= (2), and the unit of penetration depth Δ is m. In formula ω is the angular frequency: ω=2πfs; μ is magnetic conductivity, for the relative permeability of copper wire: μr=1 , 则μ=μ0×μr=4π×10－7H/m; γ is the conductivity of copper, γ = 58 × 10 —6Ωm. The operating frequency of the transformer is 50kHz, and the penetration depth of the copper conductor is Δ=0.2956mm at this frequency, thus the diameter of the winding wire must be copper wire whose diameter is less than 0.59mm. In addition, the current density of copper wire is generally 3 ~ 6 A / mm2, the 0.56mm enamelled wire with 8 strands in parallel for the primary is 10 turns, and the thick 0.15mm flat copper strip with 2 turns in the secondary.   3.4 Design of Auxiliary Power Supply The auxiliary power supply using RCC converter (Ringing Choke Converter), is shown in Fig.4. The input voltage is AC 220 V, as rectifier filter voltage, and the output DC voltage is 12.5 V, the output DC current is 0.5 A. In the circuit, Q8 and transformer primary winding N1 and feedback winding N3 constitute self-excited oscillation. R72 is starting resistance. Q9, R77 constitutes primary overcurrent protection of auxiliary power supply. D20, C81, ZD1, Q11, R75, N76 constitutes voltage detection and voltage stabilizing circuit. The DC component of the base current of Q 8 keeps the output voltage constant, and the transformer is made of EE19 material and LP3 material. The primary is 180 turns, the feedback winding is 5.5 turns, the secondary is 11 turns, the primary inductance is 2.6 MHz, the core gap is 0.4mm.   3.5 Drive Circuit The drive circuit is shown in Fig.5. TL494 outputs the pulse signal of 50kHz and drives the power MOS transistor through the coupling of a high-frequency pulse transformer. The secondary pulse voltage is a timing MOS switch, during which Q7 ends, and the drain circuit formed by it does not work. Q7 conducts when the second pulse voltage is 0, rapidly releasing the gate charge of MOS, and accelerating MOS cutoff. R70 is the spike to suppress the driving pulse, R68, D15, R67 used to speed up driving and suppress the oscillation caused by driving pulse, D17, and the connected pulse transformer windings form a demagnetization circuit.  Fig.5 Driving Circuit Schematic Diagram 3.6 Fan Wind Speed Control Circuit Fan wind speed control circuit is shown in Fig.6. Based on the decreasing trend of diode forward tube pressure drop with increasing temperature, D9 and D10 are used as radiator temperature samplers close to the radiator. When the temperature of the radiator rises with the increase of output power, the level of the positive phase input of the operational amplifier N2A decreases, the output low level causes the transistor Q3 to start conducting, and the voltage on the fan rises.   The rotational speed rises and finally reaches the maximum speed. When the load is lighter and the radiator temperature is lower than 50 ℃, the output of N2A is high level, Q3 is not conductive, and auxiliary electricity 12.5V stepped down by resistance R57 supplying to fan, thus the fan is running at low speed and low noise. The circuit can improve the working life of the fan, increase the reliability of the circuit and reduce the noise caused by the fan in the case of a small load.   Fig.6 Fan Wind Speed Control Circuit 3.7 PWM Control Circuit The general pulse width modulator (TL494,) used in the control circuit has the advantages of generality and low cost, as shown in Fig.7. The output voltage is sampled by R40, RV2, RV1, R41 and then sent to the TL494 pin 1 after the R5 impedance matching. RV1 installed in power front panel to realize the output voltage adjustment. R103 and C14 sample the output inductor L1 front signal which delivering through R5 to TL494 pin 1 to improve power supply stability and eliminate the influence of L1 on loop stability.   3.8 Current Foldback Circuit In order to enhance the reliability of the power supply, this power supply adopts two-stage over-current protection: primary and secondary. Current transformer CT1 is initially used to detect the primary transformer current. The detected current signal is converted from R60 to voltage signal, then filtered by D2~D4 and C9, and then the voltage is divided by potentiometer RV3, and inverted by N3, finally added to the Q 1 tube base. When the primary current is abnormal, the inverter reverses the Q1 switch and adds a high level of VREF=5V to the TL494 pin 4 (the TL494 dead-zone control pin, which is turned off at a high level), TL494 is off. Overcurrent protection on the main output DC line uses R45-R56 resistance as the sampling resistance. When the output current increases, the level of pin15 becomes lower. When the output current is greater than 105% of 40A, the internal operational amplifier of TL494 acts. The pin3 level rises, limiting the increase of the output pulse width, and the power supply is in the limiting state. FAQ   1. How does a switching power supply work? The “switch” in a switching power supply is actually a semiconductor – a MOSFET that is either off or on – driven into its saturation range to transfer power across nearly zero resistance. It does this many thousands of times per second, creating the high-frequency AC intermediary.   2. What is difference between linear and switching power supply? Linear power supplies deliver DC by passing the primary AC voltage through a transformer and then filtering it to remove the AC component. Switching power supplies feature higher efficiencies, lighter weight, longer hold up times, and the ability to handle wider input voltage ranges.   3. What is a switching power supply 12v? Switching regulated 12VDC power supplies, sometimes referred to as SMPS power supplies, switchers, or switched mode power supplies, regulate the 12VDC output voltage using a complex high frequency switching technique that employs pulse width modulation and feedback. Acopian switching regulated power supplies also employ extensive EMI filtering and shielding to attenuate both common and differential mode noise conducted to the line and load. Galvanic isolation is standard in our 12VDC switchers, affording our users input to output and output to ground isolation for maximum versatility. Acopian switching regulated power supplies are highly efficient, small and lightweight, and are available in both AC-DC single and wide-adjust output and DC-DC configurations.   4. What is a DC switching power supply? A Switching DC power supply (also known as switch mode power supply) regulates the output voltage through a process called pulse width modulation (PWM). The PWM process generates some high frequency noise, but enables the switching power supplies to be built with very high power efficiency and small form factor.   5. When should you use a switching power supply? Switching power supplies are primarily used in digital systems such as telecommunication devices, computing equipment, audio equipment, mobile phone chargers, medical test devices, arc welding equipment and automotive chargers.   6. Is a switching power supply regulated? A switch mode power supply regulates an output voltage with pulse width modulation (PWM). This process creates high-frequency noise but it provides a high-efficiency rating in a small form factor. ... The low DC voltage is finally converted into a steady DC output with another set of diodes, capacitors, and inductors.   7. Is a switching power supply DC? A switching power supply takes an AC input, but rectifies and filters into DC first, is converted back into AC at some high switching frequency, steps down the voltage with a transformer, then is rectified and filtered into a DC output.   8. How do I know if my power supply is regulated? You can generally stick one probe into the middle of the connector, and hold the other against the outside. With a few exceptions, the middle is positive, so use the red lead there, and use the black lead on the outside shell. Regulated supplies, without any load, should measure very close to the target voltage of 12v.   9. Can I use a switching power supply to drive a DC motor? A simple unregulated analog power supply may be easier and be able to supply the large starting under load current more that the switching one. DC motors are not too fussy about the supply, and will usually run quite well on unfiltered DC.   10. What are the 3 types of power supply? There are three subsets of regulated power supplies: linear, switched, and battery-based. Of the three basic regulated power supply designs, linear is the least complicated system, but switched and battery power have their advantages.   You May Also Like Learn Some Basic Knowledge about Capacitor Voltage Transformer The Latest Development of Electric Vehicle Power Management Technology Design a Momentary Pushbutton in the Circuit of Laching Power Switch

This article would introduce MCU in details, including analysis its internal structure, and elaborate some important concepts, especially would put emphasis on the concept of memory decoding.   Catalog I. What is MCU? II. Some Basic Concepts 2.1 The Meaning of Rom 2.2 The Meaning of Bit 2.3 The Meaning of Bytes III. The Working Principle of Memory IV. MCU Circuit v. Memory Decoding FAQ   I. What is MCU?   MCU(microcomputer) is an integrated circuit chip. It integrates the microprocessor(CPU), which has data-handling technology such as arithmetic, logic and data transfer, etc, random access data memory(RAM), read-only program memory(ROM), input and output circuit (I/O port) that using the very large scale processing-data technology and may also include a timing counter, serial communication port (SCI), display drive circuit (LCD or LED drive circuit), pulse width modulation circuit (PWM), analog multiplexer and A/D converter, which form a minimum but perfect computer system.   Under the control of software, these circuits can complete the tasks specified by the program designer accurately, quickly, and efficiently. From this point of view, the single-chip microcomputer has the function which the microprocessor does not have, it has intelligent control functions which the modern industry control request separately. And this is the single-chip microcomputer's biggest characteristic.       II. Some Basic Concepts   2.1 The Meaning of Rom Let's think about a problem: when we write instruction in a programmer into an MCU and then take off it, the MCU can execute the instruction, so the instruction must be stored somewhere in the MCU. And this place can still maintain this instruction not to be lost after it power-off. What place is this? This place is the internal ROM of MCU, which is the read-only program memory. Why do you call it read-only memory? We use the programmer, external equipment, to write to the ROM operation under special conditions. In the MCU normal working conditions,  the data can only read but can’t write in, so we call it ROM.   2.2 The Meaning of Bit From the experiment above, we already know that the level of a lamp or a line can represent two states: 0 and 1. In fact, this is a binary bit, thus we call a line a bit, expressed in BIT.   2.3 The Meaning of Bytes A line can represent 0 and 1, two lines can express 00, 01, 10, 11 four states, that is, it can express 0 to 3, and three can express 0 to 7. The computer usually put with eight lines together, counting at the same time, can represent 0 to 255, for a count of 256 states. These eight lines or 8-bit is called a byte (BYTE).   III. The Working Principle of Memory   Structure All the instructions that a single-chip microcomputer can execute are the instructional systems of it. Different kinds of single-chip computers have different instructional systems. In order for a single-chip microcomputer to automatically complete a specific task, the problems to be solved must be programmed into a series of instructions (these instructions must be recognized and executed by the selected single-chip microcomputer). These instructions integrated into the program, and the program needs to be stored in memory—a storage unit.    The memory consists of many storage units (the smallest unit of storage), just as a building has many rooms, each room in a large building is assigned a unique room number. Each storage unit must also be assigned a unique address number, which is known as the address of the storage unit so that the address of the storage cell is known. The instructions are stored in these units. The storage unit can be found, where the stored instructions can be taken out and then executed.   Memory is the place where data is stored. It uses the electricity level to store the data, that is, it actually stores the electrical level, not the number of 1234 that we are used to thinking of. A memory is like a small drawer. If there are eight small drawers in a small drawer, each one is used to store the "charge," and the charge is passed in or released through the wire attached to it. You can think of a wire as a pipe, and the charge in the grid is like water, so it's easy to understand it. Each small drawer in memory is a place for data, which we call a ''bit''.   With this structure, we can start storing data. If we want to put in a data 12, that is 00001100, and we just have to fill the second and third squares with the charge, and the other cells are free of the charges. But the problem is that memory has a lot of cells, and the lines are parallel, and when you put the charge in it, you put the charge in all the cells, and when you release the charge, you release the charge from each cell. In the case of it, no matter how many cells the memory has, it can only be put in the same number, which is certainly not what we want.    A little bit to change structurally,  there's a control line on each unit, and if you want to put the data in the unit, give a signal to the control line of the unit. Therefore, the control line turns on the switch so that the charge can flow freely. And there is no signal on the other unit control lines, so the switch turns off and will not be affected, so that if you handle the control lines of different units, you can write different data to each unit. Similarly, if you want to take data from one unit, just turn on the corresponding control switch.     IV. MCU Circuit   A circuit is always made up of components connected by wires. In analog circuits, wiring is not a problem, because there is usually a serial relationship between the devices, and there are not many connections between the devices, but the computer circuits are different. The microprocessor is the core for it, each device must be connected to the microprocessor, the work of each device must be coordinated, so it needs a lot of connections.   If still like analog circuits, there will be an amazing number of lines between microprocessors and devices, so the concept of a bus has been introduced into the microprocessor, and each device has shared the connection. All 8 data lines are connected to eight common lines, that is, the equivalent of each device is in parallel, but this is not enough. If there are two devices delivering data at the same time, one is 0 and the other is 1, what exactly does the receiver get? This situation is not allowed, so control through the control line to make the device working time-sharing, at any time there can be only one device to send data ( multiple devices can receive at the same time).      V. Memory Decoding   So how do we control the control lines of each unit? It is not that simple to lead the control lines of each unit out of the integrated circuit. There are 65,536 units in a model 27512 memory, and if each line is drawn out, the integrated circuit must have more than 60,000 feet, so it is necessary to find a way to reduce the number of lines. We have a way called decoding, briefly introduce: one line can represent two states and two lines can represent four states and three lines can represent eight kinds, and so on, thus we only need 16 lines to represent 65536 states.   Since the decoding problem solved, let's focus on another problem. Where did the eight lines in each unit come from? Actually, it is connected to the computer, in general, the eight wires not only for memory but also connected to other devices. The problem arises in this way. Because these eight wires are not dedicated to the memory and the computer, it is not good if a unit is always connected to the eight wires. For example, if the value in this memory cell is 0FFH but there one unit is OOH, then what the line set at a high level or a low level?   Thus we have to separate them. The solution is: when the outside wire is connected to the pin of the integrated circuit, it does not directly attach to the units, but a set of switches is added to the middle. Normally we leave the switch off, and if we really want to write data to this memory, or read the data out of the memory, just turn the switch on. This set of switches is selected by three leads: read control, write control, and chip selector.    To write data into the chip, select the chip first, then send a write signal, the switch turns on, and the incoming data (charge) is written into the film chip. If you want to read, select the film chip first, and then send out the read signal, the switch turns on, and the data is sent out. The read and write signals are also connected to another memory at the same time, but the chip selector ends are different.   Although there is a read or write signal, there is no chip selection signal, so the other memory will not "misunderstand" and result in a conflict. What will happen if you pick two chips at the same time? Actually, this can’t be happening because the system is designed and controlled by computer, not by the human. If any, there’s something wrong with the circuit.     From the introduction above, we have seen that the eight lines used to transmit data are not dedicated, but shared by many devices, so we call it data bus. The data line of the device is called the data bus, and all the control lines of the device are called the control bus. There are memory cells in the internal or external memory and other devices of a single chip. Units must be assigned addresses before they can be used. Of course, the assigned addresses are also given in the form of electrical signals. Because there are too many memory cells, there are many lines for address allocation, which are called address buses. Sixteen address lines are also connected, called address buses.   FAQ   1. What are the characteristics of microcomputer? a. Small size and low cost. b. One user. c. Easy to use. d. Low computing power. e. Commonly used for personal application.   2. What are the advantages of microcomputer? a. This computer is widely used today. b. The microcomputer is small in size. c. The microcomputer is used to design different software and app. d. This type of computer is a low cost, so all the users can easily buy. e. No need for highly trained staff for operating microcomputer to office work.   3. Why microcontrollers are often called single chip computers? Single-chip computers are mainly of the form known as Microcontroller chips (the most commonly known are the PIC range by Microchip inc) and used in embedded devices. They provide much more basic functionality but are far simpler to work with as they don't require any external chips in order to function.   4. What is single chip microcomputer that has everything inbuilt? This is a microcomputer built using separate components (CPU, Memory, etc.). ... For some specific applications, we also have single chip computers in a VLSI chip. This single chip microcomputer will have a CPU, memory and I/O interfaces, timers, ADC/DACs etc. on a single chip itself.   5. What is difference between microprocessor and microcomputer? The main difference between Microprocessor and Microcomputer is that the Microprocessor is a computer processor contained on an integrated-circuit chip and Microcomputer is a small, relatively inexpensive computer. ... Microprocessors contain both combinational logic and sequential digital logic.   6. Is Raspberry Pi a microcomputer? The Raspberry PI is a microcomputer that's often used by hobbyists to create projects like animated LED displays or bird watchers.   7. Which is a feature of a single chip microcomputer? A single-chip microcomputer is a major branch of a microcomputer. The biggest feature of the structure is that the CPU, memory, timer and various input/output interface circuits are integrated on a very large-scale integrated circuit chip. In terms of its composition and function, a single chip is a computer.   8. What are the components of microcomputer? The main components are: (1) the central processing unit (CPU), (2) input devices, (3) output devices, and (4) memory. The CPU of a microcomputer performs all the arithmetic, logic, and data handling functions of the microcomputer.   9. Is microcontroller a microcomputer? A Microcontroller is a small and low-cost microcomputer, which is designed to perform the specific tasks of embedded systems like displaying microwave information, receiving remote signals etc.   10. What is the definition of microcomputer? Microcomputer, an electronic device with a microprocessor as its central processing unit (CPU). Microcomputer was formerly a commonly used term for personal computers, particularly any of a class of small digital computers whose CPU is contained on a single integrated semiconductor chip.   You May Also Like Transformers Basics: Construction, Types, Materials and Design Switched Mode Power Supply Tutorial: Principles & Functions of SMPS Circuits List of Basic Electronic Components Switching Power Supply Tutorial: 4V～16V

A high-output-power balanced power amplifier is designed with power-combining architecture for satellite communication terminals. The power-combining architecture introduces a ±45° phase shift in the output matching network of two amplifiers, which makes the balanced power amplifier more tolerant to load mismatch and less sensitive to load variation. This balanced power amplifier is implemented with InGaP/GaAs HBT process. Under the band of 1.5 GHz to 1.7 GHz and the supply voltage of 5 V, the measured results show that 32 dB of the gain, 38 dBm of the saturated output power and 43% of power added efficiency (PAE) are achieved, and a good radio frequency performance can be maintained under load mismatch conditions. Power Amplifier ( PA ) Basics and fundamental tutorial on radio frequency   Catalog Ⅰ Introduction of Power Amplifier 1.1 Background of power amplifier 1.2 Application of power amplifier in   power combination scheme 1.3 High power balanced power amplifier Ⅱ Design and Analysis of balanced Power   Amplifier 2.1 Design of Integral circuit 2.2 Circuit Analysis Ⅲ Test result Ⅳ Conclusion FAQ     Ⅰ Introduction of power amplifier 1.1 Background of power amplifier In recent years, with the development of economy, satellite communication and navigation systems are widely used in electronics and automobile industry,and the demand for power amplifiers of handheld terminal transmitters is increasing.These power amplifiers require greater power output and better stability to meet the performance requirements of satellite communications and navigation systems. Therefore, it is of great significance to study the practical and reliable high power integrated power amplifier used in the handheld terminal of satellite communication and navigation system. The traditional single-terminal multi-stage integrated power amplifier is not only low in output power, due to the influence of its own semiconductor physical characteristics and the limitations of processing technology, heat dissipation, impedance matching, etc, but the output power will also decrease rapidly with the increase of frequency. In order to improve the output power, the power combination technology is a practical and easy method to implement. At the same time, the balanced power amplifier is widely used in the power synthesis scheme because of its insensitive load and wider bandwidth than the single-ended power amplifier.    1.2 Application of power amplifier in power combination scheme In reference, a high linearity and high efficiency power amplifier is realized by balanced synthesis method. The power amplifier has the advantages of flat gain characteristics and more stability than the corresponding single-ended amplifier in a wide band. However, the introduction of orthogonal 3dB couplers at the input and output ends makes the power amplifier require more discrete devices, which is not conducive to miniaturization and integration. In reference, a novel balanced synthesis architecture was used to design a load insensitive power amplifier.This kind of power amplifier adds ±45 °phase shift network to the upper input and lower output terminals, and finally combines the two power channels through the Wilkinson synthesizer at the output end. This design not only achieves high efficiency and linearity, but also has good stability when the load changes. It is widely used in 3G WCDMA mobile phone terminals. However, the introduction of Wilkinson synthesizer also brings many disadvantages, such as large insertion loss, increasing integration cost and complexity. In reference, on the basis of reference, the ±45°phase shift network in the output end of the power amplifier is improved and optimized, the Wilkinson synthesizer is removed either, which makes the power amplifier insensitive to the load change while achieving high efficiency and high linearity.This design reduces the integrated devices, reduces the cost, and is widely used in modern 3G smart phone terminals.   1.3 High power balanced power amplifier Based on the comprehensive consideration of output power and stability, a high power balanced power amplifier based on InGaP/GaAs HBT process, operating in the 1.5-1.7 GHz band, is designed in this article. The test results show that the balanced power amplifier has high output power and power addition efficiency (PAE), and the circuit can still maintain good RF performance when the load mismatches. Ⅱ Design and analysis of balanced power amplifier 2.1 Design of Integral circuit  Due to the superior linearity and high efficiency of HBT process in RF IC design, a balanced power amplifier working in 1.5-1.7 GHz band is designed by using InGaP/GaAs HBT process in this article. The overall circuit structure is shown in figure 1. The balanced power amplifier circuit includes the same upper and lower branch amplifiers, and the input and output matching circuits of ±45°phase-shifting networks. In order to obtain a higher gain, the upper and lower branches are designed using a three-stage power amplifier structure, in which the first stage works in a class A to obtain a high linearity; in order to take into account the linearity and efficiency of the overall power amplifier, the second and third stages work in Class AB.   Figure 1. A balanced power amplifier circuit   In order to achieve a good compromise between efficiency and linearity, the biasing circuit adopts self-adaptive linearizing bias.By adding one inductor and one capacitance to the input matching circuit of the upper and lower branches, the balanced power amplifier generates ±45°phase shift to the input signal, thus realizing that the upper and lower channels of the amplifier work in an orthogonal state. A LC resonant network with a resonant frequency of 2Ω0 is added to the output matching, where Ω0 is the fundamental frequency, which is equivalent to getting a load of second harmonic short circuit at the same time, thus realizing the suppression of the second harmonic. The structure is similar to that of F power amplifier, and is beneficial to obtain higher efficiency. The main characteristic of the circuit in this article is that the output matching circuit of the upper and lower branches added a ±45°phase shift network, the upper branch adds a -45°phase shift network with a low pass filter structure, and the lower branch adds a +45°phase shift network with a high pass filter structure. The balanced power amplifier designed by this synthetic structure has the advantages of small space usage, simple structure and easy implementation. At the same time, it can make the balanced power amplifier more tolerant to load mismatch and insensitive to the change of load.   2.2 Circuit Analysis When the balanced power amplifier is in operation, the input signal is coupled to the A node through the blocking capacitor, and two signals are separated from the A node into the upper and lower branches respectively, because the three-stage amplifier in the upper and lower branches is exactly the same, they sharing an equal input impedance, so the power of the two signals separated at the A node is equal. The separated signals are transmitted to the input end of the amplifier through the opposite 45°phase change of the upper and lower branches respectively, and then the orthogonal signals are amplified by the three-stage amplifier of the upper and lower branches. The orthogonal signal of the upper and lower branches undergoes an opposite phase shift of 45° in the output matching network, so the same signal with the same phase and the same amplitude is realized at point B, and the output power of point B is the sum of those of the two amplifiers, finally the balanced power amplifier can obtain higher output power. The balanced power amplifier is equivalent to the three-port network shown in figure 2. Because the upper and lower branch of amplifiers are exactly the same,it can be considered that the amplifiers of the upper and lower branches have the same output reflection coefficient ΓPA. After passing through ±45°phase shift network, we can obtain ΓPAе −j2ΔΦ and ΓPAе +j2ΔΦ respectively. Therefore, the equivalent output impedance of the upper and lower branches viewed from the ab surface to the left in figure 2 is respectively as follows:   The equivalent output impedance ZL of the network viewed from the terminal to the left can be obtained in parallel by ZL1 and ZL2: The output reflection coefficient of node B is: By substituting formula (1)-(3) into equation (4) and simplifying, the output reflection coefficient of the balanced power amplifier is as follows: When ΔΦ=45°, you have: It is shown that the output reflection coefficient and VSWR of the balanced power amplifier are twice as much as that of the single branch power amplifier. Therefore, when the load mismatch occurs, the load mismatch tolerance of the balanced power amplifier is higher than that of the single-branch power amplifier after the ±45°phase shift output matching network is introduced. Figure 2. Circuit equivalent diagram In order to analyze the performance of the balanced power amplifier in the case of load mismatch, the equivalent circuit of figure 2 is simulated and analyzed. When the load mismatch (such as VSWR=3:1), the load impedance (normalized) of the upper and lower branch amplifiers varies with the phase ψ of the reflection coefficient Γ, as shown in figure 3. By comparing the load impedance of the upper and lower branches, it can be seen that they have a phase difference of 180°. Because of the change of the load impedance of the upper and lower branches, the corresponding current is changed, and the phase difference of 180°occurs between the two. The collector of the two third-stage amplifiers of the balanced power amplifier is single power supply, so the current of the upper and lower branches compensates each other, resulting in little change in the total current, as shown in Figure 4. Therefore, when the load mismatch of the balanced power amplifier occurs, the change of working current is relatively small, that is, not sensitive to the change of load. The load insensitive effect of using this balancing architecture is similar to that of classical balanced power amplifier which is realized by using orthogonal 3 dB coupler. Figure 3. Changes in the load of the structure (normalized) when VSWR=3:1 In the case of terminal mismatch (VSWR=3:1), the single end circuit architecture and the present balanced architecture are compared as shown in Fig. 5 with the same output power of 38 dBm. It can be seen from figure 5 that the output power of the single-ended circuit architecture fluctuates greatly with of the phase ψ of the reflection coefficient Γ, while the output power of the balanced architecture in this article is relatively flat. At the same time, compared with the circuit architecture without phase shift, the in-phase circuit architecture has more advantages than the single-ended circuit architecture, but the output power of the balanced architecture is the flattest and can work stably. Figure 4. Changes of current of the structure (normalized) when VSWR=3:1 Figure 5. Comparison with the output power (normalized) changes in three kinds of circuits when VSWR=3:1   Ⅲ Test result  In this post, the balanced power amplifier is fabricated by InGaP/GaAs HBT technology. The three-stage amplifier and bias circuit with upper and lower branches are realized in the chip with an DIE area of 0.9 mm×0.8 mm. The choke inductor, input matching and output matching circuit are realized out of the chip. Considering the heat dissipation of the power amplifier, the whole thing is integrated on the Fr4 substrate with an area of 8 mm×8 mm. Figure 6 is the physical diagram of the circuit.The working voltage of the balanced power amplifier is 5 V and the total static current is about 310 mA. Using Agilent's network analyzer E5071C to measure the small signal S parameters S21, S11, S22 of the balanced power amplifier, as shown in figure 7: S21 > 31 dB (in the band of 1.5 GHz-1.7 GHz with a variation of less than 1 dB) S11 < -12 dB S22 < -10 dB The test results show that the design has good small signal performance. Using Agilent's signal generator N5182A and spectrometer N9030A to build the test platform, inputting continuous wave (CW) and the performance of the balanced power amplifier is measured at 1.5,1.616 and 1.7 GHz, as shown in figure 8. It can be seen from the diagram that the gain of the balanced power amplifier in the frequency band is about 32 dB, the in-band gain flatness is ±0.3 dB, the saturation power is more than 38 dBm/6.3 WN, and the power additional efficiency is greater than 43 dB. At the same time, according to the gain curve of each frequency point, the balanced power amplifier has good AM-AM characteristic and 1dB compression point is about 37 dBm. The third order intermodulation distortion (IMD3) and the fifth order intermodulation distortion (IMD5) of the balanced power amplifier are measured by using a two-tone signal with a deviation of 2 MHz, as shown in figure 9. The results show that the balanced power amplifier has good linearity. In general, the balanced power amplifier not only has high gain, high output power and high efficiency, but also has good linearity.  Figure 6. Chip physical diagram Figure 7. S parameter test results Figure 8. Test performance in frequency band when CW signal is input In order to verify the tolerance of the balanced power amplifier to the load mismatch and the load insensitivity, and the balanced power amplifier can still work properly when VSWR=20:1, a microwave manual tuner is connected to the output of the power amplifier. And when the working frequency is 1.616 GHz, the input power Pin=10 dBm and voltage standing-wave ratio VSWR=3:1, the output power of the balanced power amplifier changes with the reflection coefficient phase, as shown in Figure 10. The figure shows that the output power is about 35.7 dBm, with a range of ±0.7 dBm. Therefore, the performance of the balanced power amplifier is stable when the load is mismatched to a certain extent. Figure 9. Test performance of IMD3 and IMD5 Figure 10. Changes of output power when VSWR=3:1 Ⅳ Conclusion In this post, a high power balanced power amplifier is designed by using the balance architecture, the chip area is 8 mm×8 mm by using InGaP/GaAs HBT process and the total static current is about 310 mA at a operating voltage of 5V. When the CW signal is input, the gain can be up to 32 dBm in the band of 1.5-1.7 GHz, the saturation output power psat is 38 dBm, and the additional power efficiency is 43%. Beyond that, it can still work stably when the load mismatches. This balanced power amplifier is practical, reliable and safe, and can be used in handheld terminal of the satellite communication and navigation system.   FAQ     1. What is a power amplifier used for? The function of a power amplifier is to raise the power level of input signal. It is required to deliver a large amount of power and has to handle large current. The base of transistor is made thicken to handle large currents.   2. How does a power amplifier work? The power amplifier works on the basic principle of converting the DC power drawn from the power supply into an AC voltage signal delivered to the load. Although the amplification is high the efficiency of the conversion from the DC power supply input to the AC voltage signal output is usually poor.   3. Does a power amp make a difference? A better amp will make your speakers play louder and sound better, but it won't make bad speakers sound like good speakers. Many speakers have a "maximum wattage rating" on the back. ... High-end amplifier companies make amps with more than 1,000 watts, and you could plug in a $50 speaker into it with no problem.   4. What is power amplifier circuit? A power amplifier circuit is used to drive the loads like speakers with minimum output impedance. ... In this mode the output is an inverted amplified signal which is at low power. Two Darlington power transistors are arranged in a class AB configuration to amplify the power level of this signal.   5. How do you make a power amp circuit? Amplifier power gain and design. As power is the voltage multiplied by the current in a circuit, the power gain can simply be expressed as the product of the two. It is also possible to use the voltage and current levels to provide gain expressed in dB, but any changes in impedance must be accounted for.   6. What is balanced amplifier? A balanced amplifier has two amplifying devices that are run in quadrature. That is, they are operating 90 degrees apart in transmission phase. ... Balanced amplifiers may more immune to load pull effects than in-phase power combining schemes, because the two reflection coefficients are seen 180 degrees out of phase.   7. What is the difference between amplifier and power amplifier? The crucial difference between a voltage amplifier and a power amplifier is that a voltage amplifier increases the voltage level of the applied input signal.   8. Why do we need power amplifier? The function of a power amplifier is to raise the power level of input signal. It is required to deliver a large amount of power and has to handle large current. The base of transistor is made thicken to handle large currents.   9. What power amplifier do I need? Generally you should pick an amplifier that can deliver power equal to twice the speaker's program/continuous power rating. This means that a speaker with a “nominal impedance” of 8 ohms and a program rating of 350 watts will require an amplifier that can produce 700 watts into an 8 ohm load.   10. Does a power amp improve sound quality? No, amplifiers don't improve sound quality. They just increase the signals to required levels. However if amplifiers have equaliser or other signal processing facility, they can make it sound different and possibly more suitable for listening pleasure. But again that is the work of signal processing part of amplifier.  

IntroductionWhat is the IC package? To put it simply, chip packaging is the process of placing a bare integrated circuit chip produced in a foundry on a load-bearing substrate, leading the pins out, and then fixing the package as a whole. It is analogous to the chip's shell, which can wrap, fix, and seal the chip to protect it from external forces such as water, air, moisture, chemicals, and so on.With the continuous improvement of IC packaging, there are more and more types of IC packaging. Various IC packaging packages types, names, logos, etc. can sometimes be confusing. This blog will give you a brief introduction to IC packaging related content, which mainly includes the following three parts: common IC brand identification, IC package terminology, classification of IC packaging, and hope to help you further effectively distinguish and understand IC packaging. Catalog IntroductionEvolution of IC Packaging TypeIC Packaging Types10 Common IC Brand Identification71 kinds of IC package terminology   explainedFAQ Evolution of IC Packaging TypeIn the early stage of the development of chip packaging, there are mainly two types: 1. Through-hole package2. Surface mount packageThrough hole package mainly includes Dual In-line Package (DIP), Transistor Outline (TO), Pin Grid Array (PGA) and so on. Through-hole packageSurface mount package includes TO-252 (D-PAK), Small-Outline Transistor (SOT), Small Outline Package (SOP), Plastic Quad Flat Package (QFP), Plastic Leaded Chip Carrier (PLCC) and so on.Surface mount packageDue to the increasing demand of the surface mount market, the earlier through-hole TO packaging has also begun to develop to the surface mount mode. For example, DPAK packaging, which is easy for many people to confuse, actually refers to TO-252, D2PAK refers to TO-263 and D3PAK refers to TO-268.In the middle and later stage, chip packaging began to enter the era of area array packaging. During this period, packaging types such as Ball Grid Array Package (BGA), Chip Scale Package (CSP), Quad Flat No-lead Package (QFN) and Multi-Chip Module (MCM) began to become popular.With the further development of packaging technology, some chips have begun to adopt the latest three-dimensional stacking packaging technology. IIC Packaging TypesAccording to the different port direction, the common IC packages can be divided into four categories: unilateral, bilateral, four-sided and matrix and several types can be subdivided from the above four categories according to different packaging forms and port shapes. Please refer to the following table for details. IC packaging types In addition, according to the material medium, IC packaging can also be divided into metal, ceramic, plastic and other types, generally distinguished by prefix. For example, "C" refers to ceramic package, "H" refers to package with heat sink and "P" refers to plastic package. 10 Common IC Brand IdentificationMany integrated circuit models’ prefix is often the abbreviation of the manufacturer's name. If you see the following prefix model, you might as well check the corresponding brand first. Of course, this method is not entirely feasible. So you still have to refer to the PDF file of the specific product according to the actual situation.1. AMDThose prefixed with AM are all AMD products, and there are also some confusion between the prefix PAL, CYPRESS and TI. The specific situation should be determined by checking the information.2. ATMELThose prefixed with AT are ATMEL products.3. CYPRESSThose prefixed with CY are all CYPRESS products, and some of them are confused with prefix PALC, PALCE and TI.4. NSCThose prefixed with DM, LF, LM, DS, etc., are basically NSC products. NSC has many product series with other prefix, but the specific situation should be determined by checking the information.5. AD：Those prefixed with AD, OP are AD brand. AD has many other series, such as prefix: DAC, ADG, ADSP and many other series.6. INTERSIL：Those prefixed with HI1, HI2, HI3, HI4, HA1, HA2, HA3, HA4, CA, ICL, ICM, ID, IS, etc., are INTERSIL products. There is also some confusion between prefix MD and INTEL.7. IDT：The prefix for IDT products is almost the prefix IDT.8. MAXThe prefix for MAX products is almost the prefix MAX.9. AGILENTCommon prefixes are HCPL, HDSP, HSSR, and so on.10. ALTERAThe prefix for ALTERA products is almost the prefix for EPM. IC package Figure (105 kinds in total)71 kinds of IC package terminology explainedStill not sure what some IC packaging terms mean exactly? Here is a list of 71 common IC packaging terms for you.1. BGA (Ball Grid Array)BGA is one of the surface mount packages. Spherical bumps are made on the back of the printed substrate to replace pins. LSI chips are assembled on the front of the printed substrate, and then sealed by molding resin or filling method. It is also known as Pad Array Carrier (PAC) and the number of pins can exceed 200. It is a kind of package for multi-pin LSI.The package was developed by Motorola and was first used in portable phones and other devices. 2. BQFP (Quad Flat Package with Bumper)BQFP is one of the QFP packages that is provided with protrusions (cushions) at the four corners of the package body to prevent bending deformation of the pins during transportation. American semiconductor manufacturers mainly use this package in microprocessors and Asic circuits. The center distance of the pin is 0.635 mm, and the number of pins ranges from 84 to 196. (see QFP). 3. Butt Joint PGA (Butt Joint Pin Grid Array)Butt Joint PGA is an alias for surface mount PGA (see Surface Mount PGA) 4. C- (Ceramic)C- is a mark that represents a ceramic package and is often used in practice. For example, CDIP represents Ceramic DIP. 5. CerdipThe Ceramic Dual In-line Package sealed with glass is for circuits such as ECL RAM, DSP (Digital Signal Processor). Cerdip with glass window is used for ultraviolet erasing EPROM and microcomputer circuit with EPROM. The center distance of the pin is 2.54 mm, and the number of pins ranges from 8 to 42. In Japan, this package is represented as DIP-G (G means glass seal). 6. CerquadOne of the surface mount packages, that is, the lower sealed Ceramic QFP, is used to package logic LSI circuits such as DSP. Cerquad with windows is used to package EPROM circuits. The heat dissipation is better than that of Plastic QFP, and power ranges from 1.5 to 2W can be allowed under natural air cooling conditions. But the cost of packaging is 3 to 5 times higher than that of Plastic QFP. Pin center distance has 1.27 mm, 0.8 mm, 0.65 mm, 0.5 mm, 0.4 mm and other specifications. The number of pins ranges from 32 to 368. 7. CLCC (Ceramic Leaded Chip Carrier)Ceramic Leaded Chip Carrier is one of the surface mount packages, and the pins are drawn from the four sides of the package in T-shaped. Those with windows are used for packaging ultraviolet erasing EPROM and microcomputer circuit with EPROM, etc. This packaging is also known as QFJ and QFJ-G (see QFJ). 8. COB (Chip on Board)Chip on Board package is one of the bare chip mounting technologies. The semiconductor chip is connected and mounted on the printed circuit board, the electrical connection between the chip and the substrate is realized by the lead stitching method. Next, cover it with resin to ensure its reliability. Although COB is the simplest bare chip mounting technology, its packaging density is far lower than that of TAB and reverse chip welding technology. 9. DFP (Dual Flat Package)Dual Flat Package is another name for SOP (see SOP). This was once called in the past, but now it is basically out of use.10. DIC (Dual In-line Ceramic Package)This is another name for Ceramic DIP (including glass seal) (see DIP). 11. DIL (Dual In-Line)DIL is an alias for DIP (see DIP). European semiconductor manufacturers often use this name. 12. DIP (Dual In-line Package)Dual In-line Package is one of the through hole packages. The pins are drawn from both sides of the package, and the packaging materials are plastic and ceramic. DIP is the most popular through-hole package, including standard logic IC, memory LSI, microcomputer circuit and so on. The center distance of the pin is 2.54 mm, and the number of pins ranges from 6 to 64. The packaging width is usually 15.2 mm. Some refer to packages with widths of 7.52 mm and 10.16 mm as skinny DIP and slim DIP (narrow DIP, respectively). In most cases, however, it is indistinguishable and is simply collectively referred to as DIP. In addition, Ceramic DIP sealed with low melting point glass is also known as Cerdip (see Cerdip). 13. DSO (Dual Small Out-lint)DSO is the alias for SOP (see SOP). Some semiconductor manufacturers use this name. 14. DICP (Dual Tape Carrier Package)DICP is one of the TCP (loaded packages). The pins are made on the insulation tape and drawn from both sides of the package. Due to the use of TAB (Tape Automated Bonding) technology, the package shape is very thin. It is commonly used in liquid crystal display drive LSI, but most of them are customized products. In addition, the 0.5 mm thick memory LSI thin package is in the development stage. In Japan, DICP is named DTP according to the standard of EIAJ (Japanese Electronic Machinery Industry). 15. DIP (Dual Tape Carrier Package)As we mentioned above, it is the name of DTCP in the standard of the Japanese Electronic Machinery Industry Association. (see DTCP). 16. FP (Flat Package)FP is one of the surface mount packages and it is another name of QFP or SOP (see QFP and SOP). Some semiconductor manufacturers use this name.17. Flip-chipFlip-chip is one of the bare chip packaging technologies. The metal bump is made in the electrode region of the LSI chip, and then the metal bump is connected to the electrode area on the printed substrate by pressure welding. The occupied area of packaging is basically the same as the size of the chip, which is the smallest and thinnest of all packaging technologies. 18. FQFP (fine pitch quad flat package)FQFP usually refers to the QFP which the center distance of the pin is less than 0.65 mm (see QFP). Some conductor manufacturers use this name.19. CPAC (Globe Top PAD Array Carrier)CPAC is another name for BGA by Motorola in the United States. 20. CQFP (Quad Fiat Package with Guard Ring)CQFP is one of the plastic QFP. The pins are masked with a resin protective ring to prevent bending deformation. Before assembling the LSI on the printed substrate, we need to cut off the pin from the protective ring and make it become L-shaped. This package has been mass produced by Motorola in the United States. The center distance of the pin is 0.5 mm, and the maximum number of pins is about 208.21. H- (with heat sink)H- represents a mark with a heat sink. For example, HSOP represents a SOP with a heat sink.22. Pin Grid Array (surface mount type)PGA is usually a through-hole package with a pin length of about 3.4 mm. The surface mount PGA has display–shaped pins on the bottom of the package, ranging in length from 1.5 mm to 2.0 mm. Mounting uses the method of butt joint with the printed substrate, so it is also known as butt joint PGA. Because the center distance of the pin is only 1.27 mm, which is half smaller than the through-hole PGA, the package body cannot be made very large, and the number of pins is more than the through-hole type (ranges from 250 to 528). It is a package for large-scale logical LSI. The packaging substrate has a multi-layer ceramic substrate and a glass epoxy resin printing base. Packaging based on multi-layer ceramic substrate has been practical. 23. JLCC (J-Leaded Chip Carrier)JLCC refers to the alias for windowed CLCC and windowed Ceramic QFJ (see CLCC and QFJ). The name used by some semiconductor manufacturers. 24. LCC (Leadless chip carrier)LCC refers to a surface mount package with only electrode contact and no pin on the four sides of the ceramic substrate. It is a high-speed and high-frequency IC package, also known as Ceramic QFN or QFN-C (see QFN). 25. LGA (Land Grid Array)LGA , that is, an array state flat electrode contact package made on the bottom surface. All we need to do is to insert the socket when assembling. Ceramic LGA, with 227 contacts (1.27 mm center distance) and 447 contacts (2.54 mm center distance) has been used in high speed logic LSI circuits. LGA can accommodate more input and output pins in a smaller package than QFP. In addition, because of the small impedance of the lead, it is very suitable for high-speed LSI. However, due to the complexity of socket production and high cost, it is basically not used much now. But the demand for it is expected to increase in the future. 26. LOC (Lead on Chip)LOC is one of the LSI packaging technologies. The front end of the lead frame is located at the top of the chip. A convex solder joint is made near the center of the chip, and the lead is stitched for electrical connection. Compared with the original structure in which the lead frame is arranged near the side of the chip, the chip contained in the package of the same size is up to about 1 mm wide. 27. LQFP (Low Profile Quad Flat Package)LQFP is a kind of QFP whose package body thickness is 1.4 mm and this is the name used by the Japanese Electronics and Machinery Industry according to the new QFP shape specification. 28. L-QUADL-QUAD is one of the Ceramic QFP. The thermal conductivity of aluminum nitride for packaging substrate is 7 to 8 times higher than that of alumina and has good heat dissipation. The frame of the package is sealed with alumina and the chip is sealed by filling method, thus the cost is suppressed. It is a package developed for logical LSI that allows 3 w power under natural air cooling conditions. LSI logic packages with 208 pins (0.5 mm center distance) and 160 pins (0.65 mm center distance) have been developed and put into mass production in October 1993. 29. MCM (Multi-Chip Module)MCM is a package that assembles multiple bare semiconductor chips on a wiring substrate. According to the substrate materials, it can be divided into MCM-L, MCM-C and MCM-D. MCM-L is a module that uses the usual glass epoxy resin multi-layer printed substrate. The wiring density is not that high and the cost is low. MCM-C is a module which uses thick film technology to form multi-layer wiring and uses ceramics (alumina or glass-ceramic) as substrate, which is similar to mixing IC with thick film of multi-layer ceramic substrate. There is no significant difference between them, and the wiring density was higher than that of MCM-L.MCM-D is a module which uses thin film technology to form multi-layer wiring and uses ceramics (alumina or aluminum nitride) or Si and Al as substrate. The wiring density is the highest of the three modules, but the cost is also high. 30. MFP (Mini Flat Package)MFP is another name for plastic SOP or SSOP (see SOP and SSOP) and it is used by some semiconductor manufacturers. 31. MQFP (Metric Quad Flat Package)MQFP is a classification of QFP according to the JEDEC standard. It refers to standard QFP with a pin center distance of 0.65 mm and a body thickness of 3.8 mm~2.0 mm (see QFP). 32. MQUAD (Metal Quad)MQUAD is a kind of QFP package developed by Olin Company in the United States. The substrate and cover are made of aluminum and sealed with adhesive. The power of 2.5 w~2.8 w can be allowed under the condition of natural air cooling. SHINKO ELECTRIC INDUSTRIES CO., LTD. was licensed to start production in 1993. 33. MSP (Mini Square Package)MSP is another name for QFI (see QFI) and is often called in the early days of development. QFI is the name specified by the Electronic Machinery Industry Association of Japan. 34. OPMAC (Over Molded Pad Array Carrier)OPMAC is the name used by Motorola for molded resin seal BGA (see BGA). 35. P- (plastic)P- is the mark that represents a plastic package. For example, PDIP represents Plastic DIP. 36. PAC (Pad Array Carrier)PAC is an alias for BGA (see BGA). 37. PCLP (Printed Circuit Board Leadless Package)Fujitsu of Japan uses the name for Plastic QFN (Plastic LCC) (see QFN). The center distance of the pin can be divided into two specifications: 0.55 mm and 0.4 mm. It is currently in the development phase. 38. PFPF (Plastic Flat Package)PFPF is an alias for Plastic QFP (see QFP) and it is used by some LSI manufacturers. 39. PGA (Pin Grid Array)PGA is one of the through-hole packages, and the vertical pins on the bottom are arranged in the form of display. The packaging substrate is basically multi-layer ceramic substrate. In the case of not specifically indicating the name of the material, most of the Ceramic PGA, are used in high-speed and large-scale logic LSI circuits. The cost is high. The center distance of the pin is usually 2.54 mm, and the number of pins ranges from 64 to 447. In order to reduce the cost, the packaging substrate can be replaced by glass epoxy resin printing substrate. There is also Plastic PGA with 64 to 256 pins. In addition, there is a short pin surface mount PGA (Butt Joint PGA) with a pin center distance of 1.27 mm. (see Surface Mount PGA). 40. Piggy BackIt refers to a ceramic package with sockets and its shape is similar to that of DIP, QFP and QFN. It is used to confirm operation on the evaluation program when developing a device with a microcomputer. For example, plug the EPROM into the socket for debugging. This kind of package is basically custom-made, and there is little circulation on the market. 41. PLCC (Plastic Leaded Chip Carrier)PLCC is one of the surface mount packages. The pin is drawn from the four sides of the package in the shape of T and is made of plastic. Texas Instruments was first used in 64k-bit DRAM and 256k-bit DRAM, and now it has been widely used in logic LSI, DLD (or logic device) and other circuits. The center distance of the pin is 1.27 mm, and the number of pins ranges from 18 to 84. The J-shaped pin is not easy to deform and is easier to operate than QFP, but the appearance inspection after welding is more difficult.PLCC is similar to LCC (also known as QFN). In the past, the only difference between the two was that the former used plastic and the latter used ceramics. But now there are J-shaped pin packages made of ceramics and pin-free packages made of plastic. (marked as plastic LCC, PC LP, P-LCC, etc.) Thus they have been unable to distinguish.To this end, the Japanese Electronics and Machinery Industry decided in 1988 to refer to packages with J-shaped pins on four sides as QFJ, and packages with electrode bumps on four sides as QFN (see QFJ and QFN). 42. P-LCC (Plastic Leadless Chip Carrier)Sometimes it is another name for Plastic QFJ, sometimes it is another name for QFN (Plastic LCC) (see QFJ and QFN). Some LSI manufacturers use PLCC for lead package and P-LCC for lead-free package to show the difference. 43. QFH (Quad Flat High Package)QFH is a kind of Plastic QFP. In order to prevent the package body from breaking, the QFP body is made thicker (see QFP). This is the name used by some semiconductor manufacturers. 44. QFI (Quad Flat I-leaded Package)QFI is one of the surface mount packages. The pin is drawn from the four sides of the package in I-shaped. It is also known as MSP (see MSP). The mount is connected with the printed substrate by butt joint. Because there is no protruding part of the pin, the occupied area of the mount is smaller than that of QFP. Hitachi has developed and used this package for video analog IC. In addition, this package is also used by PLL IC of Motorola, a Japanese company. The center distance of the pin is 1.27 mm, and the number of pins is from 18 to 68.45. QFJ (Quad Flat J-leaded Package)QFJ is one of the surface mount packages. The pin is drawn from the four sides of the package in the shape of J. It is the name stipulated by the Japan Electronic Machinery Industry Association. The center distance of the pin is 1.27 mm. There are two kinds of materials: plastic and ceramics. Plastic QFJ is mostly called PLCC (see PLCC), and it is for microcomputers, gate displays, DRAM, ASSP, OTP, etc. The number of pins ranges from 18 to 84. Ceramic QFJ is also known as CLCC and JLCC (see CLCC). The windowed package is used for ultraviolet erasing EPROM and microcomputer chip circuits with EPROM. The number of pins ranges from 32 to 84.46. QFN (Quad Flat Non-leaded Package)QFN is one of the surface mount packages and it is often called LCC now. QFN is the name specified by the Electronic Machinery Industry Association of Japan. The four sides of the package are equipped with electrode contacts. Because there are no pins, the mounting area is smaller than QFP, and the height is lower than QFP. However, when there is a stress between the printed substrate and the package, it cannot be alleviated at the electrode contact. Therefore, it is difficult for electrode contacts to make as many pins as QFP. The number of pins is generally ranges from 14 to 100.There are two kinds of materials: ceramic and plastic. When marked with LCC, they are basically Ceramic QFN. The center of the electrode contact is 1.27 mm.Plastic QFN is a low-cost package for printing substrate with glass epoxy resin. In addition to 1.27 mm, there are two kinds of electrode contact center distance: 0.65 mm and 0.5 mm. This package is also known as Plastic LCC, PCLC, P-LCC and so on.47. QFP (Quad Flat Package)QFP is one of the surface mount packages, with pins drawn from four sides in L-shaped. There are three kinds of substrate: ceramic, metal and plastic. In terms of quantity, plastic packaging accounts for the vast majority. When the material is not specifically indicated, most of the cases are Plastic QFP. Plastic QFP is the most popular multi-pin LSI package. It is not only used in microprocessor, gate display and other digital logic LSI circuits, but also in VTR signal processing, audio signal processing and other analog LSI circuits. The center distance of pin has 1.0 mm, 0.8 mm, 0.65 mm, 0.5 mm, 0.4 mm, 0.3 mm and other specifications. The maximum number of pins in the 0.65 mm center distance specification is 304.In Japan, QFP with a pin center distance less than 0.65 mm is called QFP (FP). But now the Japanese Electronics and Machinery Industry will re-evaluate the shape of the QFP. There is no difference in the center distance of the pin. But according to the thickness of the package body, it can be divided into three types: QFP (2.0 mm~3.6 mm thickness), LQFP (1.4 mm thickness) and TQFP (1.0 mm thickness).In addition, some LSI manufacturers specifically refer to the QFP with the pin center distance as 0.5 mm as shrink QFP or SQFP, VQFP.However, some manufacturers also call the QFP with pin center distance of 0.65 mm and 0.4 mm SQFP, which makes the name a little confused. The disadvantage of QFP is that when the center distance of the pin is less than 0.65 mm, the pin is easy to bend. In order to prevent pin deformation, several improved QFP varieties have emerged such as BQFP with tree finger buffer pads on the four corners of the package (see BQFP); GQFP with a resin protection ring which covers the front of the pin (see GQFP) and TPQFP (see TPQFP)，which is set test bumps in the package body and can be tested in a special fixture to prevent pin deformation.In the aspect of logical LSI, many development products and highly reliable products are packaged in multi-layer ceramic QFP. Products with a minimum pin center distance of 0.4 mm and a maximum number of pins of 348 have also been introduced. In addition, there are glass-sealed ceramic QFP.48. QFP (FP) (QFP fine pitch)This is the name specified in the standard of the Japan Electronic Machinery Industry Association. The pin center distance is 0.55 mm, 0.4 mm, 0.3 mm and so on, which is smaller than that of 0.65 mm (see QFP).49. QIC (Quad In-line Ceramic Package)QIC is another name for Ceramic QFP and it is used by some semiconductor manufacturers (see QFP, Cerquad).50. QIP (Quad In-line Plastic Package)QIP is another name for Ceramic QFP and is used by some semiconductor manufacturers (see QFP, Cerquad).51. QTCP (Quad Tape Carrier Package)QTCP is one of the TCP packages that forms pins on the insulation tape and leads out from the four sides of the package. It is a thin package using TAB technology (see TAB, TCP).52. QTP (Quad Tape Carrier Package)QTP is the name used by the Japanese Electronic Machinery Industry for the shape specifications developed by QTCP in April 1993 (see TCP).53. QUIL (Quad In-Line)QUIL is an alias for QUIP (see QUIP).54. QUIP (Quad In-line Package)The pin is drawn from both sides of the package and bends down into four columns at every other pin. The pin center distance is 1.27 mm. When inserted into the printed substrate, the insertion center distance becomes 2.5 mm. Therefore, it can be used for standard printed circuit boards.It is smaller package than the standard DIP. Nippon Electric has adopted this kind of package in microcomputer chips for desktop computers and household appliances. There are two kinds of materials: ceramics and plastics. The number of pins is 64. 55. SDIP (Shrink Dual In-line Package)SDIP is one of the through-hole packages with the same shape as the DIP. Its pin center distance (1.778 mm) is less than DIP (2.54 mm) so it gets this name. The number of pins ranges from 14 to 90. It is also known as SH-DIP. There are two kinds of materials: ceramics and plastics.56. SH-DIP (Shrink Dual In-line Package)SH-DIP is the same as SDIP and it is used by some semiconductor manufacturers. 57. SIL (Single In-Line)SIL is an alias for SIP (see SIP). European semiconductor manufacturers often use this name. 58. SIMM (Single In-line Memory Module)A memory module provided with electrodes only near one side of the printed substrate. It usually refers to a module inserted into a socket. The standard SIMM has two specifications: 30 electrodes with center distance of 2.54 mm and 72 electrodes with center distance of 1.27 mm. The SIMM with 1 megabit and 4 megabit DRAM packaged with SOJ on one or both sides of the printed substrate has been widely used in personal computers, workstations and other devices. There are at least 30 to 40 percent of DRAM is installed in SIMM. 59. SIP (Single In-line Package)The pins are drawn from one side of the package and arranged in a straight line. The package is laterally mounted on the printed substrate. The center distance of the pin is usually 2.54 mm, and the number of pins ranges from 2 to 23, most of which are customized products. Packages come in different shapes. Sometimes packages with the same shape as ZIP are called SIP.60. SK-DIP (Skinny Dual In-line Package)SK-DIP is a kind of DIP which has a narrow body with a width of 7.62 mm and a pin center distance of 2.54 mm. It is often collectively referred to as DIP (see DIP).61. SL-DIP (Slim Dual In-line Package)SL-DIP is a kind of DIP which has a narrow body with a width of 10.16 mm and a pin center distance of 2.54 mm. It is commonly referred to as DIP. 62. SMD (Surface Mount Devices)Occasionally, some semiconductor manufacturers classify SOP as SMD (see SOP).63. SO (Small Out-line)SO is another name for SOP and is used by many semiconductor manufacturers in the world. (see SOP).64. SOI (Small Out-line I-leaded Package)SOI is one of the surface mount packages. The pin is drawn down from both sides of the package in I-shaped, with a center distance from 1.27 mm and 26 pins. The occupied area of mounting is smaller than that of SOP. Hitachi uses this package in analog IC (IC for motor drive).65. SOIC (Small Out-line Integrated Circuit)SOIC is an alias for SOP (see SOP). Many semiconductor manufacturers abroad use this name.66. SOJ (Small Out-Line J-Leaded Package)SOJ is one of the surface mount packages. The pin is J-shaped from both sides of the package, so it gets its name. They are usually plastic products and are used in memory LSI circuits such as DRAM and SRAM. But most of them are used in DRAM.Many of the DRAM devices packaged in SOJ are mounted on SIMM. The center distance of the pin is 1.27 mm, and the number of pins ranges from 20 to 40 (see SIMM).67. SOL (Small Out-Line L-leaded Package)The name used for SOP in accordance with the JEDEC standard (see SOP).68. SONF (Small Out-Line Non-Fin)SONF is the SOP without heat sink. As the same as the usual SOP, the NF (non-fin) mark is intentionally added In order to show that there is no heat sink in the power IC package. The name is used by some semiconductor manufacturers (see SOP).69. SOF (Small Out-Line Package)SOF is one of the surface mount packages with pins drawn from both sides of the package in L-shaped. There are two kinds of materials: plastic and ceramics. And it is also known as SOL and DFP.SOP is not only used for memory LSI, but also widely used in small-scale ASSP and other circuits. SOP is the most popular surface mount package in areas where the input and output terminals do not exceed 10 to 40. The center distance of the pin is 1.27 mm, and the number of pins is from 8 to 44.In addition, a SOP with a pin center distance less than 1.27 mm is also known as a SSOP. A SOP with assembly height less than 1.27 mm is called TSOP (see SSOP, TSOP). There is also a SOP with a heat sink. 70. SOW [Small Outline Package(Wide-Type)]SOW refers to wide body SOP and this name is used by some semiconductor manufacturers.71. COG (Chip on Glass)COG (Chip on Glass) packaging technology, which has great influence on the development of Liquid Crystal Display (LCD) technology, is becoming more and more practical in the world.FAQ 1. What is package in IC?The case, known as a "package", supports the electrical contacts which connect the device to a circuit board. In the integrated circuit industry, the process is often referred to as packaging. Other names include semiconductor device assembly, assembly, encapsulation or sealing.2. What are the different types of IC packages?What is IC packaging?DIP (Double In-line Package)SOP/SOIC/SO (Small Outline Package)QFP (Quad Flat Package)QFN/LCC (Quad Flat Non-leaded Package)BGA (Ball Grid Array Package)CSP (Chip Scale Package)3. What is IC and how it works?An integrated circuit, or IC, is small chip that can function as an amplifier, oscillator, timer, microprocessor, or even computer memory. An IC is a small wafer, usually made of silicon, that can hold anywhere from hundreds to millions of transistors, resistors, and capacitors.4. What are the types of ICs?Below is the classification of different types of ICs basis on their chip size.SSI: Small scale integration. 3 – 30 gates per chip.MSI: Medium scale integration. 30 – 300 gates per chip.LSI: Large scale integration. 300 – 3,000 gates per chip.VLSI: Very large scale integration. More than 3,000 gates per chip.5. How do I know my IC type?How to Identify Integrated Circuit ChipsIdentify the manufacturer first. ...Look up data sheets in the manufacturer's printed catalog. ...Look up a part number in an electronic retailer's catalog. ...Use the technical specifications for a piece of equipment to find part numbers and alternates.6. What is the most common type of digital IC package?DIP (Dual in-line packages)DIP, short for dual in-line package, is the most common through-hole IC package you'll encounter. These little chips have two parallel rows of pins extending perpendicularly out of a rectangular, black, plastic housing.7. What are the advantages of IC?The advantages of ICs : (i) Extremely small in size, (ii) Low power consumption, (iii) Reliability, (iv) Reduced cost, (v) Very small weight and (vi) Easy replacement. 8. What is the IC package?What Is the Package in IC? IC packaging refers to the material that contains a semiconductor device. The package is a case that surrounds the circuit material to protect it from corrosion or physical damage and allow mounting of the electrical contacts connecting it to the printed circuit board (PCB). 9.Why IC packaging is important?IC packaging is the ability to provide more and more I/O interconnections to a die (bare chip) that is increasingly shrinking in size is an ever-present problem.10. What are the three basic types of linear IC packages?IC packages can be grouped into three general categories; Dual In-line Packages, Chip Carriers and Grid Arrays. All the packages, regardless of the category has a body style that scales with pin count.

ⅠIntroduction Motor capacitors temporarily store an electrical charge to provide additional torque and improve the performance and efficiency of a motor. Start capacitors provide added torque during motor startup and then exit the circuit when the motor reaches operating speed. Run capacitors assist the motor in maintaining a consistent charge while it is running. By balancing working power and supplied power, power factor correction capacitors reduce motor power consumption caused by heavy inductive loads. Motor capacitors are most frequently used to power motors in HVAC applications such as fans, blowers, and compressors, but they are also found in pumps, conveyors, and machine tools. What does a run capacitor look like? Catalog ⅠIntroduction Ⅱ Two Types of Motor Capacitor 2.1 What is the run capacitor？ 2.2 What is the starter capacitor? Ⅲ Run Capacitor Related Video Ⅳ Specifications of Run Capacitor Ⅴ Faulty Run Capacitor 5.1 When Is It Time to Replace a Run Capacitor? 5.2 Causes of Failure Ⅵ How To Replace a Start Run Capacitor? Ⅶ How Do They Work In an HVAC System? Ⅷ Dual Capacitors vs. Run Capacitors vs. Run Capacitors   Ⅱ Two Types of Motor Capacitor Motor capacitor include two types: run capacitor and starter capacitor. Let us have a look at the two capacitors.   2.1 What is the run capacitor？ Run capacitors are rated in the 3–70 microfarad range (uF). Voltage classification is also applied to rate run capacitors. The voltage levels are 370V and 440V. Starting capacitors have ratings greater than 70 microfarads (uF). Run capacitors are designed for continuous duty and remain energized throughout the lasting of the motor's operation. A capacitor is required to power a second phase winding in a single-phase electric motor. This is why the sizing is so crucial. The motor will not have an even magnetic field if the incorrect run capacitor is installed.This case will lead to the rotor hesitating at uneven spots. This pause causes the motor to become noisy, increases energy consumption, reduces performance, and causes the motor to overheat.   2.2 What is the starter capacitor? In contrast to run capacitors, which have a specific uF rating, starting capacitors are housed in a black plastic case and have an uF range. Start capacitors (with ratings of 70 microfarads or higher) are classified into three voltage classes: 125V, 250V, and 330V. A 35 uF at 370V run capacitor and an 88–108 uF at 250V start capacitor are two examples. Start capacitors increase motor starting torque and allow a motor to be rapidly cycled on and off. Start capacitors are designed for one-time use only. Start capacitors are energized for a short time, allowing the motor to reach 3/4 of its full speed before being disconnected from the circuit.   Ⅲ Run Capacitor Related Video   Start Capacitors & Run Capacitors for Electric Motors - Differences Explained by TEMCo run capacitor video descriped:  What's the difference between a start capacitor and a run capacitor? Can you use them interchangeably? See why these two types of capacitors cannot always be substituted for one another.   Ⅳ Specifications of Run Capacitor Most run capacitor applications employ capacitance ratings of 2.5-100 uf (microfarads) and voltages of 370 or 440 VAC. They are also usually rated at 50 and 60 Hz. Cases are typically round or oval in shape, with a steel or aluminum shell and cap. Terminals are typically 14" push-on terminals with 2-4 terminals per connection post.   Specifications of Run Capacitor   Ⅴ Faulty Run Capacitor 5.1 When Is It Time to Replace a Run Capacitor? As a general rule, a run capacitor will greatly exceed the start capacitor of the same motor. A run motor capacitor will wear down at different levels, making it more complicated to determine if it needs to be replaced. When a run capacitor begins to perform outside of its allowable range, the rated capacitance value usually drops. A "tolerance" will be specified for most standard motor run capacitors, describing how close the actual value may be to the rated capacitance value. It is usually within +/- 5% to 10%. For most motors, as long as the actual value is within 10% of the rated value, you're good to go. A run capacitor will occasionally bulge from internal pressure due to a flaw in the capacitor's construction or a non-capacitor-related motor issue. Most modern run capacitor designs will open the circuit, disconnecting the internal spiral membrane as a precautionary measure to keep the capacitor from popping. The test is simple: it is time to replace in both cases that it is  bulging and there is  no continuity between the terminals, Run Capacitor   5.2 Causes of Failure Depending on how close the run capacitor is to its design life, there could be several reasons why it failed.   Diagnosing and Replacing a Run Capacitor   Ⅵ How To Replace a Start Run Capacitor? When a new motor is installed, a new fan capacitor should always be installed. It is always a good idea to photograph or write down the wire coloring and connections. Turn off the power to the HVAC unit and use a meter to ensure it is completely off.Locate and remove the side panel where the electricity is fed into the unit.Locate the Stat Run Capacitor;  there will only be one in a Dual Run capacitor. If there are two, only the fan motor capacitor has to be replaced.Check the MFD and voltages, then connect the new connections from the old capacitor to the new capacitor one leg at a time to ensure they are correct. (For example, if you have two capacitors, one is for the compressor and the other is for the fan motor.)   Ⅶ How Do They Work In an HVAC System? A Start or Run Capacitor can be combined into a single capacitor with three leads known as a Dual Capacitor, or it can be split between two separate capacitors. The Start Capacitor gives a fan motor the torque it needs to start spinning and then turns off, whereas the Run Capacitor stays on and provides extra torque to the motor when needed. The motor will most likely not start if the Start Capacitor fails. If a Run capacitor fails, the motor will start, but the running amperage will be higher than usual, causing the motor to run hot and have a short life expectancy. There are three connections on a Dual Capacitor: HERM, FAN, and COM. HERM is for the Hermetically Sealed Compressor, FAN is for the Condenser Fan Motor, and COM is for the Contactor, which powers the Capacitor. If the unit has two capacitors, the larger of the two is the Run Capacitor. Keep in mind that the compressor frequently necessitates the use of a HERM capacitor (compressor). Run Capacitor circuit   Ⅷ Dual Capacitors vs. Run Capacitors vs. Run Capacitors The only benefit we can get from the dual-run capacitor design is that it comes in a small package with only three connections. Aside from that, there is no distinction between run and dual run capacitors. If there is enough space for mounting, it is acceptable to replace your original dual-run capacitor with two separate run capacitors. They typically have "C" connections for "common," "H" or "Herm" connections for "Hermetic Compressor," and "F" connections for "Fan." They'll also have two different capacitor ratings for the two parts. Start capacitors provide a high capacitance value required for motor starting in a very short (seconds) time. They are only designed for intermittent duty and will fail catastrophically if left on for an extended time. Run capacitors are continuous duty because they provide continuous voltage and current control to a motor's windings. They typically have a much lower capacitance value.   Ⅸ FAQ 1. What happens when a run capacitor goes bad? A bad motor capacitor may cause starting problems or could shut off the motor while running. Same principle on the dirty coil. ... If a Run capacitor goes bad then a motor can turn on but the running amperage will be higher than normal causing the motor to run hot and have a short life expectancy. 2. What is the difference between a capacitor and a run capacitor? The start capacitor creates a current to voltage lag in the separate start windings of the motor. The current builds up slowly, and the armature has an opportunity to begin rotating with the field of current. A run capacitor uses the charge in the dielectric to boost the current which provides power to the motor. 3. Can I run my AC without a capacitor? Most of the motors in your air conditioner can't run without a good capacitor. Like I said, they support these motors. They help the motor start and run efficiently. Some people have gone out to their air conditioner and noticed the fan wasn't spinning on their AC as it should be. 4. Can I use a run capacitor in place of a start capacitor? The capacitance and voltage ratings would have to match the original start capacitor specification. A start capacitor can never be used as a run capacitor, because it cannot not handle current continuously. 5. Do I need a start or run capacitor? Run capacitors are designed for continuous duty, and are energized the entire time the motor is running. Single phase electric motors need a capacitor to energize a second phase winding. ... Start capacitors increase motor starting torque and allow a motor to be cycled on and off rapidly. 6. What size run capacitor do I need? The run capacitor should have the exact microfarad (uf) that the motor is rated for. Capacitors rated above 70uf are considered Start Capacitors and are generally removed from the circuit electrically during operation. This is where the rule of +/- 10% of the rating came from, for Start Capacitors ONLY!

  Solid-state drive or Solid-state disk, abbreviated as SSD, is a computer storage device made of integrated circuits. You can use non-volatile memory (mainly NAND Flash in flash memory) as a permanent storage device, or use volatile memory (such as DRAM) as a temporary storage device. Solid-state hard drives often use SATA, PCI Express, mSATA, M.2, ZIF, IDE, U.2, CF, CFast... and other interfaces. At present, due to the difference between the price per unit and the maximum storage capacity of the mechanical hard disk, the solid state hard disk cannot completely replace the mechanical hard disk for the time being.   How do SSDs Work? | How does your Smartphone store data?  Catalog I What is Solid State Drive? II SSD Classification 2.1 Solid State Drive based on FLASH   Memory 2.2 Solid State Drive based on DRAM III Development History IV SSD Basic Structure 4.1 Main Control Chip 4.2 Cache Chip 4.3 Flash Memory Chip V Compare with Traditional Hard Disk VI SSD Advantages and Disadvantages 6.1 SSD Advantages 6.2 SSD Disadvantages FAQ I What is Solid State Drive?  Solid State Drive, also called solid state disk or SSD, is a hard disk made from an array of solid-state electronic memory chips, consisting of a control unit and a memory unit (FLASH chips / DRAM chips). The interface specification and definition, function and usage method of solid state disk are identical to those of ordinary hard disk drive, and the product shape and size are also the same as that of ordinary hard disk drive.  The working temperature range of SSD chip is very wide: Commercial product: 0~70℃; Industrial product: -40~85℃. Although the cost of manufacturing an SSD is high, it is still gradually being popularized into the DIY market. Due to the difference between solid state drive technology and traditional hard disk drive technology, there are many new memory manufacturers. Manufacturers only need to buy NAND memory, and then they can manufacture solid state disk with proper control chip. The new generation solid state drive generally uses SATA-2 interface, SATA-3 interface, SAS interface, MSATA interface, PCI-E interface, NGFF interface, CFast interface and SFF-8639 interface. II SSD Classification There are two kinds of storage media in solid state drive, one is FLASH chip and the other is DRAM. 2.1 Solid State Drive based on FLASH Memory Solid state drive based on FLASH memory(IDE FLASH DISK, Serial ATA Flash Disk) is using FLASH chips as its storage media. Its appearance can be made into a variety of forms, such as: Laptop hard drive, Micro hard disk, memory card, USB flash disk and etc. The biggest advantage of this SSD is that it is movable, and the data protection is not controlled by power supply. Also, it can be applied to various environments, but its service life is not too long, so it is suitable for individual users. In a flash-based solid state drive, memory cells are divided into two categories: SLC (Single Layer Cell) and MLC (Multi-level Cell).  Solid state drive based on FLASH memory The characteristics of SLC is its high cost, small volume and high speed. And for MLC, it is with characteristics of large volume, low cost but low speed. Each unit of MLC is 2bit, which is exactly twice as many as SLC. However, due to the large amount of data stored in each MLC storage cell and the relative complexity of the structure, the probability of error will increase, so the error correction must be carried out. This action will cause its performance to lag significantly behind the SLC flash memory with simple structure. In addition, the advantage of flash memory is that the number of duplicates is up to 100000 times, which is 10 times higher than that of MLC flash memory. In order to ensure the lifetime of MLC, the control chip is calibrated and the intelligent wear balance algorithm is used, so that the write times of each memory cell can be divided equally, and the mean time between failures (MTBF) can reach 1 million hours.   2.2 Solid State Drive based on DRAM Solid state drive based on DRAM is using DRAM as the storage medium. However, its application range is currently narrow. It follows the design of traditional hard disk, which can be volume setup and managed by most file system tools of operating system, and provides industrial standard PCI and FC interfaces for connecting hosts or servers. The application can be divided into two kinds: SSD hard disk and SSD hard disk array. It is a kind of high performance memory and has a long service life. The downside of it is its need for independent power supply to protect the data security. Solid state drive based on DRAM III Development History > 1956: IBM invented the world's first hard disk. > 1968: IBM restates the feasibility of Winchester technology, which established the development direction of hard disk. > 1970: StorageTek developed the first solid state hard drive. > 1989: The world's first solid state hard disk occurred. > 2006.03: Samsung took the lead in launching a solid state hard disk laptop with 32GB capacity > 2007.01: SanDisk released an 1.8-inch solid state hard disk with 32GB and 2.5-inch model with 32GB in March. > 2007.06: Toshiba has launched its first solid-state hard disk laptop with 120GB capacity. Intel SSD 520 Series > 2008. 09: The official launch of MemoRight SSD marks the accelerated entry of Chinese enterprises into solid state hard disk industry.  > 2009: With the development of SSD , all the manufacturers crushed into this industry , and the storage virtualization then entered a new stage . > 2010.2: Magnesia released the world's first solid-state disk with SATA 6Gbps interface, which breaking through the speed of SATAII interface reading and writing(300MB/s). > The end of 2010: Renice launched and patented the world's first high-performance mSATA solid state disk. > 2012: Apple uses 512GB solid state hard drives on its laptops. > 2015.08.01: TEKISM introduced the first mobile solid-state hard disk with Type-C interface. The SSD provides the latest Type-C interface and supports double-sided insertion of the USB interface. > 2016.01.01: Chinese storage company TEKISM has released the world's first Type-C fingerprint encrypted SSD. SSD M300   IV SSD Basic Structure The FLASH based SSD is the main category of solid state drives. Its internal structure is very simple. The main body of the solid state hard disk is actually a PCB board, and the most basic accessory on this PCB board is the control chip, cache chip(some low-end disks have no caching chip) and NAND flash that used for data storage. The more common solid state hard drives on the market are: LSISandForce, Indilinx, JMicron, Marvell, Phison, Goldendisk and Samsung. The main control chip is the brain of solid state hard drive. One of its functions is to reasonably allocate the load of data on each flash memory chip, and the other is to transfer the whole data and connect the flash memory chip with the external SATA interface. The ability of different master control is very different in data processing ability, algorithm, flash chip reading and writing control , which will directly lead to a ten times gap of solid state hard disk performance. Different SSD 4.1 Main Control Chip Table 1. Brand, model and product of the main control chip for solid state drive 4.2 Cache Chip   The cache chip is next to the main control chip. Solid state drive and traditional hard disk both require high speed cache chip to assist the main control chip for data processing. It is important to be noted here that there are some cheap solid state drive solutions to save the cost of the cache chip, which will have a certain impact on the performance in use.   4.3 Flash Memory Chip Apart from main control chip and caching chip, chips on the other place on PCB board are mainly NAND Flash chips. NAND Flash memory chips are divided into SLC, MLC and TLC NAND Flash memory.    V Compare with Traditional Hard Disk The interface specification and definition, function and usage method of solid state drives are almost the same as those of ordinary hard disk, and the shape and size of solid state drives are basically the same as that of ordinary 2.5 inch hard disk. Solid state drive has the advantages of fast reading and writing, light mass, low power consumption and small volume, which is not possessed by traditional mechanical hard disk. At the same time, its disadvantage is obvious. Although IDC believes that SSD is in the mainstream of the storage market, its price is still relatively high and its capacity is relatively low, once the hardware is damaged, the data is difficult to recover, and others think that the durability of solid state drives is relatively short. The main factors that influence the performance of solid state drive are main control chip, NAND flash media and firmware. Under the same conditions, what kind of interface is adopted may also affect the performance of SSD. The mainstream interface is SATA (including two kinds of interfaces for 3Gb/s and 6Gb/s) and the SSD of the PCIe 3.0 interface. Duo to the difference of the design and the principle of data reading and writing between SSD and the common disk, the internal structure of SSD is also very different. In general, the structure of solid state disk (SSD) is relatively simple and can be disassembled; therefore, most of the articles we see about SSD performance evaluation include an internal disassembly diagram of SSD. On the other hand, the data reading and writing of the ordinary mechanical disk is to lift the magnetic head by the air produced by the high speed rotation of the disc, which makes the magnetic head infinitely close to the disk without contact, and the stepper motor is used to push the head to read the data of changing the track. Therefore, its internal structure is relatively complex, more sophisticated, which is generally not allowed to disassemble. Once human disassembly, there is a strong risk of damage on the disk and disk can not work properly.This is why disassembly diagrams are largely invisible when evaluating ordinary disks.   VI SSD Advantages and Disadvantages 6.1 SSD Advantages   6.1.1 Fast reading and writing Using flash memory as storage medium, the read speed of SSD is faster than mechanical hard disk. SSD does not use (magnetic) head, and its seek time is almost 0. The speed of continuous writing is amazing, and most SSD manufacturers will claim that their solid state drives continue to read and write faster than 500MB / s! The speed of solid state hard disk is not only reflected in continuous reading and writing, but also in random reading and writing speed, which is directly reflected in most of the daily operation. Associated with this are extremely low access times, with the most common 7200 rotary mechanical drives running at 12-14 milliseconds, while solid state drives can easily reach 0.1 milliseconds or less.    6.1.2 Shock resistance Traditional hard drives are disk-type, data is stored in the disk sector. The solid state drive is made from flash memory particles (mp3, U disk, etc.), so there are no mechanical components inside the SSD. This will not affect its normal use even when moving at high speed or even with tilting, and minimize the possibility of data loss in the event of collisions and oscillations. Compared with the traditional hard disk, solid state drive has an absolute advantage.   6.1.3 Low power consumption  The power consumption of solid state drive is lower than that of traditional hard disk.   6.1.4 Noiseless Solid state drive has no mechanical motors and fans inside, thus it works with a noise value of 0 dB.Flash based solid state drives have lower energy consumption and lower calorific emissions (but the consumption of high-end or large-capacity products will be larger). There are no mechanical parts inside, so there will be no mechanical failure, no collision, no shock or vibration. Because the solid state hard disk uses the flash memory chip without mechanical parts, it has the characteristics of low heat emission and fast heat dissipation.   6.1.5 Wide range of working temperature A typical hard disk drive can only work in the range of 5 to 55℃ and most solid state drives can work at -10~70℃. The solid state hard disk is smaller in size and lighter in weight than the mechanical disk of the same capacity. The interface specification and definition, function and usage method of solid state drives are the same as those of ordinary hard disk, and the product shape and size are the same as that of ordinary hard disk. The working temperature range of the chip is very wide(-40~85 ℃).   6.1.6 Lightweight Solid state drives are lighter in weight, 20-30 grams lighter than regular 1.8-inch hard disks.   6.2 SSD Disadvantages  6.2.1 Capacity The maximum capacity of solid state drive is only 4TB. It is SanDisk Optimus MAX   6.2.2 Limited Service Life Solid state drive flash memory has the problem of limitation of erasing times.  A flash memory is completely erased once called a P / E, so the life of flash memory takes P/E units. The lifetime of the 34nm flash chip is about 5000 P / E, while the lifetime of the 25nm is about 3000 P / E. With the improvement of SSD firmware algorithm, the new SSD can provide less unnecessary writing. An 120GB solid state drive that writes 120GB of files to one P / E. In practical use, individual users often write in random rather than continuously. So there will be higher probability of bad sectors. In addition, while each sector of the solid state drive can be repeatedly erased 100000 times(SLC), in some applications such as LOG records in operating system , A sector may be read and written over and over again, in which case the actual lifetime of a solid state disk is not yet tested. However, with the equalization algorithm, the life expectancy of the memory unit is increased by 100000 writes, and the low cost MLCs have only 10, 000 write lives, while the cheap TLC flash memory is only 500 to 1, 000 times.   6.2.3 Expensive The price of the 128GB solid state drive on the market is around RMB550, while the price of the 256GB is around RMB950 .   FAQ   1. Is SSD better than HDD? SSDs in general are more reliable than HDDs, which again is a function of having no moving parts. ... SSDs commonly use less power and result in longer battery life because data access is much faster and the device is idle more often. With their spinning disks, HDDs require more power when they start up than SSDs.   2. What is a solid state drive used for? A solid-state drive (SSD) is a solid-state storage device that uses integrated circuit assemblies to store data persistently, typically using flash memory, and functioning as secondary storage in the hierarchy of computer storage.   3. Is a 256GB SSD better than a 1TB hard drive? A 1TB hard drive stores eight times as much as a 128GB SSD, and four times as much as a 256GB SSD. The bigger question is how much you really need. In fact, other developments have helped to compensate for the lower capacities of SSDs.   4. Do I need HDD if I have SSD? You don't need both but having a SSD for your operating system and a HDD for your storage drive might be the best bang for your buck. Otherwise, you only need one; a HDD is cheaper, larger, slower, and more prone to data loss. A SSD are normally smaller in storage for the same price but faster and shock resistant.   5. Should I upgrade to SSD? It's time to upgrade to an SSD if you're still using a mechanical hard drive in your computer. ... Solid-state drives are so much faster because they don't have a spinning magnetic platter and moving head. After upgrading, you'll be amazed at the performance improvements and wondering why you waited so long.   6. What are the pros and cons of a solid state drive? a. SSD is faster. b. SSD can take a licking c. HDD is cheaper; SSD is still expensive. d. HDD has greater storage capacity than SSD   7. Do solid state drives crash? SSDs can fail, but in a different way than traditional HDDs. While the latter often fail because of mechanical issues, SSDs may fail due to the methods used to write information. ... Each P/E cycle gradually degrades the memory of an SSD's cells until they eventually become worn down.   8. Can I put SSD and HDD together? The answer is absolutely yes. You can install both, but, SSD will have faster SSD speeds and HDD will still have slower HDD speeds. It is an excellent idea to use SSD and HDD at the same time. An SSD boasts many distinctive merits such as fast loading speed, low power consumption, and etc.     9. How much faster is a SSD than a HDD? As noted above,solid-state drives can read/write speeds of around 550 MB/s faster than a hard disk drive. SSDs can go even faster, provided your computer can handle it. A PCIe SSD can achieve anywhere from 1.2 GB/s to 2.2 GB/s - assuming you have a motherboard that can handle these speeds.   10. How can I tell if my SSD is failing? So here are four signs of SSD failure: Sign #1: Your computer takes a long time to save files. Sign #2: You have to restart often. Sign #3: Your computer crashes during boot. Sign #4: You receive a read-only error.