The Kynix Blog - Resistors

IntroductionFor people who have been in touch with digital circuits or analog circuits, the 555 IC is definitely classic work. With its low cost and reliable performance, it is widely used in various electrical appliances, including instruments and meters, household appliances, electric toys, and automatic control. The 555 timer only needs a few external resistors and capacitors to realize pulse generation and conversion circuits, such as multiple oscillators, monostable triggers and schmitt triggers. So how does it work in the circuit? What the role of its circuit? Here gives several typical 555 circuit examples for specific analysis.555 Timers Circuit LearningCatalogIntroductionⅠ Basic 555 Timer Circuit AnalysisⅡ 555 Multivibrator Circuit AnalysisⅢ 555 Timer Monostable Flip Flop Circuit AnalysisⅣ Classic 555 Timer Circuits DiagramsⅤ 555 Timer IC ModesⅠ Basic 555 Timer Circuit Analysis555 Means What?555 timer is a convenient and powerful IC, which is widely used in signal generation, conversion, control and detection. The origin of this name, because it is divided by three 5KΩ resistors. The 555 timer is a simple integrated circuit that can be used to make many different electronic circuits. With the following circuits analysis you will know how 555 IC works.Figure 1. Basic 555 Timer Circuit✔️ Circuit AnalysisR is not the reset terminal, when set to 0, Q is 0,  is 1, Uo outputs 0, and is 1 added to the base of the transistor T, the transistor is in the conducting state.① When R=0, Q=1, uo=0, T is saturated and turned on.② When R=1 (there is no reset function at this time):UTH>2VCC/3, UTR>VCC/3, C1=0, C2=1, Q=1 or =0, uo=0, T is saturated and turned on. (Analysis: C1's positive input terminal is 2VCC/3, C1's negative input UTH terminal is greater than the positive input terminal, working in saturation, and output 0. C2's negative input terminal is 1VCC/3, which is smaller than the positive input Terminal UTH, and outputs 1. There is a horizontal line above RD and SD, which means low level, meaning is Reset. C1 outputs 0, RD is valid, then Q is 0, not 1, Uo outputs 0, and is not acting on the base of the triode.)③ When R=1, UTH<2VCC/3, UTR>VCC/3, C1=1, C2=1, Q and remain unchanged, uo and T remain unchanged. (Analysis is the same as above)④ When R=1, UTH＜2VCC/3, UTR＜VCC/3, C1=1, C2=0, Q=0, =1, uo=1, T is cut off. (Analysis is the same as above) Learn how the inputs interact with the supply voltage to trigger and reset the output high and low. Find out which pins can be used to adjust the threshold at which that change happens.Ⅱ 555 Multivibrator Circuit AnalysisFigure 2. 555 Multivibrator Circuit Analysis Figure 3. 555 Multivibrator Circuit Example✔️ Circuit Analysis First, the power supply VCC charges the capacitor C through R1 and R2, and the voltage of the capacitor must be relatively small, less than 1VCC/3. Similarly, the positive terminal of C1 is 2VCC/3, the negative terminal of C2 is 1VCC/3, and the TH and TR terminals are connected At the same time, it is less than 1VCC/3 at the beginning. At this time, C1 outputs 1, C2 outputs 0, and the set terminal is valid (with detailed confirmation): Q is 1, is not 0, and uo is 1, the transistor is cut off, and outputs high level. At this time, the power supply is still charging the capacitor. When the TH and TR terminals are connected together, the voltage is less than 2VCC/3 and greater than 1VCC/3; C1 outputs 1, C2 outputs 1, the transistor is cut off, and uo is 1. When the capacitor is greater than 2VCC/3, C1 outputs 0 and C2 outputs 1. At this time, Q is 0, is not 1, uo is 0, the output is low, and the transistor is turned on. The capacitor will be discharged through pin 7. After this, the voltage at the point where TH and TR connected will gradually decrease, less than 2VCC/3 and greater than 1VCC/3, and then it will be less than 1VCC/3, to form a harmonic oscillator.The pulse width tp1 of the first transient state, that is, the time required for uc to rise from VCC/3 charging to 2VCC/3 (charged through two resistors):The second transient state pulse width tp2, that is, the time required for uc to discharge from 2VCC/3 to VCC/3:Duty cycle: the time that the high level occupies the entire cycle., it can be seen that its duty cycle is always greater than 50%.Examples 1Circuit with Adjustable Duty Cycle (add an adjustable resistor)Figure 4. Circuit with Adjustable Duty Cycle (add an adjustable resistor)It can be calculated:Where T1=0.7R1C (T1 is charging time), T2=0.7R2C (T2 is discharging time)Total time T=T1+T2=0.7(R1+R2)CSo R1, R2, and C are determined, and the period T is also determined.Duty Cycle Calculation Example 2Circuit with Adjustable Duty Cycle (1KHz)Figure 5. Circuit with Adjustable Duty Cycle (1KHz)✔️ Circuit AnalysisT = 0.7(R1+R2)C, f = 1/T, the duty cycle circuit only needs to adjust the resistance value. Ⅲ 555 Timer Monostable Flip Flop Circuit AnalysisWorking Characteristics① It has two different working states: steady state and transient state.② Under the action of an external trigger pulse, it can switch from the steady state to the transient state. After the transient state is maintained for a period of time, the circuit can automatically return to the steady state.③ The transient state cannot be maintained for a long time, and the duration of its sustaining time depends on the parameters of the circuit itself and has nothing to do with the trigger pulse. So what is the principle of a monostable circuit?Figure 6. 555 Timer Monostable Circuit Analysis Figure 7. 555 Timer Monostable Circuit Example✔️ Circuit AnalysisFirst, the TR terminal is at a high level ui, which must be greater than 1VCC/3. At this time, C2 outputs 1, and the power supply charges capacitor C through R. The charging voltage is less than 1VCC/3 (TH), CO voltage is equal to 2VCC/3, C1 outputs 1, and it is in the holding state at this time. Assuming that the non-reset terminal of R is reset before power on, the output of uo is 0, and then the previous state is still maintained and the output is 0 at this time. is 1, the transistor is turned on, the capacitor is discharged through pin 7, and uc is zero level. At a certain moment, ui is low, C1 still outputs 1, C2 outputs 0, Q is 1, is 0, uo outputs 1 (high level), and the transistor has been in the cut-off state. At this time, VCC can charge the capacitor (uc is getting larger). When uc is between 1VCC/3~2VCC/3, assuming that the TR terminal returns to the original state (high level), C1 outputs 1 , C2 outputs 1, at this time uo keeps in original state, it is still 1, and the transistor is in the cut-off state. When uc is greater than 2VCC/3, C2 is still 1, C1 output is 0, Q is 0, is 1, and uo is 0, the transistor is turned on and in a discharging state, at this time, uc is getting smaller and smaller.Summery:1. As long as a low-level trigger signal is given, the temporary stable stay time is the charging time of voltage 0V~ 2Ucc/3 (the time represented by tp).2. Charging time Tp=1.1RC3. It can be used as a timing circuit, and the time can be determined by RC.Example: Timing Circuit Design (1s delay time)Figure 8. 555 Timer Delay Circuit ExampleⅣ Classic 555 Timer Circuits DiagramsThere are A LOT of projects out there using the 555 in various ways and it’s easy to find schematics to make a project that has already been proven. Here lists some typical projects using 555 timer in circuits. Let’s have a look. 🔺 Car Tachometer🔺 SIREN🔺 Flashing Lights🔺 Knight Rider Circuit🔺 Laser Ray🔺 Latch🔺 LED Dimmer🔺 555 Amplifier🔺 Light Detector🔺 Machine Gun🔺 Metal Detector🔺 Motor PWM🔺 Music Box🔺 Zener Diode Tester Ⅴ 555 Timer IC Modes555 timer will use different models in different circuits to meet circuit requirements. Therefore, it has many derivative models produced by different companies with different pin functions, and uses CMOS design. What;s more, some chips include several integrated 555 timers. Some common models of the 555 chip family are as follows:ManufacturerModelRemarksCustom Silicon SolutionsCSS555/CSS555CCMOS chip, minimum working voltage 1.2V, IDD < 5µACEMIULY7855*ECG SemiconductorsECG955MTimer Single Rc-type OscillatorExarXR-555Highly stable controllerFairchildNE555/KA555Time-delay or mono-stableHarrisHA555*IK SemiconILC555CMOS chip, minimum working voltage 2VTexas InstrumentsSE555/NE555*RenesasICM7555CMOS RC timersLithic SystemsLC555Available in Industry's Smallest 8-Bump DSBGAMaximICM7555CMOS RC timers, minimum working voltage 2VMotorolaMC1455/MC1555Monolithic timerNational SemiconductorLM1455/LM555/LM555C*National SemiconductorLMC555CMOS chip, minimum working voltage 1.5VNTE SylvaniaNTE955MAccurate time delaysRaytheonRM555/RC555*RCACA555/CA555C*STMicroelectronicsNE555N/ K3T647*Texas InstrumentsSN52555/SN72555*Texas InstrumentsTLC555CMOS chip, minimum working voltage 2VZetexZSCT1555Precision single cell timerNXPICM7555CMOSHitachi SemiconductorHA17555Accurate time delays or oscillations Frequently Asked Questions about 555 Timer Circuit1. What does a 555 timer do in a circuit?The 555 timer IC is a very cheap, popular and useful precision timing device which can act as either a simple timer to generate single pulses or long time delays, or as a relaxation oscillator producing a string of stabilised waveforms of varying duty cycles from 50 to 100%. 2. How much voltage can a 555 timer take?The standard TTL 555 can operate from a supply voltage between 4.5 volts and 18 volts, with its output voltage approximately 2 volts lower than its supply voltage VCC. The 555 can source or sink a maximum output current of 200mA, (but it may get hot at this level), so the circuit variations are unlimited. 3. What are the modes of operation of a timer?The timer registers can be used in two modes. These modes areTimer mode and the Counter mode. The only difference between these two modes is the source for incrementing the timer registers. 4. What are the basic operation modes of the 555 timer?The operating modes of a 555 timer are astable, bistable and monostable. Each mode of operation signifies with a circuit diagram and its output. 5. What is the maximum frequency of a 555 timer?2MHzaccording to the website, the 555 timer has a maximum frequency of 2MHz.

IntroductionAs everyone knows, in order to create a passive low pass filter, combing resistive elements with reactive elements happens often. Put simply, a typical circuit composed of resistors and capacitors or inductors. According to theories, the resistor–inductor (RL) low-pass topology is equivalent to the resistor-capacitor (RC) low-pass topology in terms of filtering capability. However. in fact, RC low pass filters are more common, so this article will focus on first-order RC low pass filters.In this video, Passive RC Low Pass Filter has been discussed. CatalogIntroductionⅠ Typical RC Circuit1.1 Time Domain1.2 Frequency DomainⅡ First-order Low Pass Filter on Software2.1 Basic Filtering Algorithm2.2 Basic Algorithm of First-order RC Digital FilteringⅢ Optimization Method- Filtering Coefficients AdjustmentⅠ Typical RC CircuitThe RC circuit has thousands of uses and is a very important circuit to study. Not only can it be used to time circuits, it can also be used to filter out unwanted frequencies in a circuit and used in power supplies, like the one for your computer, to help turn ac voltage to dc voltage.Figure 1. Typical RC Circuit (DC, AC, and Pulse Signals can all use it)1.1 Time DomainCapacitor Current:According to Kirchhoff’s Voltage Law:Where, the unit of Ui is volts, the unit of RC is seconds, and τ=RC, get:Suppose the initial voltage of the capacitor is 0, where:R=1000ΩC=4.7uFUi=1Vt=0.0001~0.1sτ=RCVc(τ)=0.632 Figure 2. Step Response Curve of a First-order RC System1.2 Frequency DomainTaking the capacitor voltage as the output, the network function of the circuit is:Where u1=Ui, u2=UoLet ωc be equal to:, which is the cut-off frequency.Amplitude and phase angle function:Value of variables:R=1000ΩC=4.7uF |A(fc)|=0.707θ(fc)=-45, f=0.001, 1, …….100000.Amplitude and phase frequency characteristics:Figure 3.Figure 4.Logarithmic representation of amplitude-frequency characteristic:Figure 5.Analysis:When ω<ωc, the amplitude is a straight line parallel to the coordinate, and there is no attenuation.　When ω>ωc, it is a straight line whose slope is proportional to -20dB/decade.When ω=ωc, the gain is attenuated to 0.707, which is -3dB, and the phase lags by 45 degrees, corresponding to a low-pass filter. This frequency is usually called the cutoff frequency. Disadvantages:When using this analog filter to suppress low-frequency interference, the filter is required to have a larger time constant and a high-precision RC network. Increasing the time constant requires increasing the value of R, and meanwhile, the leakage current increases accordingly, thereby reducing the filtering effect.Figure 6. RC CircuitⅡ First-order Low Pass Filter on SoftwareAdvantages1) The use of digital filtering algorithms to achieve dynamic RC filtering can well overcome the shortcomings of analog filters.2) This kind of algorithm is more practical when the simulation constant is required.3) It has a good inhibitory effect on periodic interference.4) Save RAM space Disadvantages1) Exit phase lag, resulting in low sensitivity.2) It cannot filter out interference with a frequency higher than half of the sampling frequency (called the Nyquist frequency. For example, if the sampling frequency is 100 Hz, it cannot filter out interference signals above 50Hz). In this case, an analog filter should be used.3) For the single-chip microcomputer without multiplication and division running instructions, the workload of the program operation is relatively large.2.1 Basic Filtering AlgorithmOrigin of the AlgorithmThe transfer function of the first-order RC low-pass filter in the S domain for frequency analysis:Through z-transformation (there are many methods, such as first-order forward difference, bilinear transformation, etc. Here, the first-order backward difference method is used): Into the S-domain Transfer Function After the derivation is transformed into the difference equation, we can get:The transfer function in the S domain can be transformed into a difference equation in the time domain through the Z transformation.2.2 Basic Algorithm of First-order RC Digital FilteringX is the input, Y is the output value after filtering, then: a is a parameter related to the RC value, called the filter coefficient, its value determines the weight of the new sample value in the filtering result of this time, and its value is usually far less than 1, when the sampling interval t is small enough:1) The smaller the filtering coefficient, the smoother the filtering result, but the lower the sensitivity.2) The larger the filtering coefficient, the higher the sensitivity, but the more unstable the filtering result.3) The output value this time mainly depends on the last filtered output value, and the current sampled value has a relatively small effect on this output, which plays a corrective role.4) Cutoff frequencyFor example: t=0.5s (f=2Hz), a=1/32where fl=(1/32)/(2*3.14*0.5)=0.01Hz Basic ProgramWrite the program according to the basic principles and formulas of first-order filter, as follows:/*In the program, integer arithmetic is faster than decimal arithmetic. In order to speed up the processing speed of the program, for calculation convenience, a is an integer (from 0~255), 1-a is replaced by 256-a, which means that the new sample value is being filtered. The weight in the result (you can also change the base of 1-a to 100-a, and the calculation result will be processed accordingly)*/#define a 128 char value; //Last filtering valuechar filter(){    char new_value;    new_value=get_ad();//Sampling value    return(256-a)*value/256+a*new_value/256；}Initial Optimization of the ProgramReduce the number of operations of multiplication and division to increase the speed of operations.Specific optimization methods:First compare the new sampled value with the previous filtering result, and then use different formula calculations based on the comparison, so that the calculation efficiency of the program is doubled.Resolve the basic formula to get: ProcessNotes:S → New Sampling ValueR → Previous Filtering ResultC→ Filter CoefficientN→ New Filtering Result Program/*Int: NEW_DATA     New sampling values       OLD_DATA       Last filtering result       k        Filter coefficient (0~255)  Out:         The filtering results */ char filter_1(char NEW_DATA,char OLD_DATA,char k){    int result;    if(NEW_DATA<OLD_DATA)    {        result=OLD_DATA-NEW_DATA;        result=result*k;        result=result+128;//+128 Round Up        result=result/256;        result=OLD_DATA-result;    }    else if(NEW_DATA>OLD_DATA)    {        result=NEW_DATA-OLD_DATA;        result=result*k;        result=result+128;//+128 Round Up        result=result/256;        result=OLD_DATA-result;    }    else result=OLD_DATA;    return((char)result);} Filtering AnalysisWhen the filtering coefficient is 30:Figure 7.When the filtering coefficient is 128:Figure 8.When the filtering coefficient is 200:Figure 9.It can be seen that the smaller the filtering coefficient, the smoother the filtering result, but the lower the sensitivity. On the contrary, the larger the filtering coefficient, the higher the sensitivity, but the more unstable the filtering result.Insufficient1) The contradiction between sensitivity and smoothness2) Errors caused by discarding decimals.For example: the current sampling value=25, the last filtering result=24, and the filtering coefficient=10;According to the algorithm, the filtering result of this time = 24.0390625In single-chip microcomputers, floating-point numbers are rarely used, and the fractional part is either discarded or needs to round up. In this way, the result is 24. If the sampling value is always 25, the result will always be 24. Because the filtering result and the actual data will always have an error that cannot be eliminated. Sometimes it will cause the filtering result curve to deviate from the actual value when the sampling data is stable at a certain value (that is, there is a large error between the filtering result and the actual result although in a stable case). Be Careful1) Changing the filtering coefficient, increasing it will reduce the smoothness, and if it is too large, the filtering will lose its meaning.2) The use of decimal part in calculations will bring heavy computational pressure to the CPU. Ⅲ Optimization Method- Filtering Coefficients AdjustmentRealize the Function1) When the data changes rapidly, the filtering results can be followed up in time, and the faster the data changes, the higher the sensitivity should be (sensitivity priority principle).2) When the data becomes stable and oscillates within a range, the filtering result can become stable (the principle of stability first).3) When the data is stable, the filtering result can be approximated and finally equal to the sampling data (eliminate the error caused by decimals in the calculation). Judgment before Adjustment1) Whether the data changes consistently. For example, when the two consecutive sampling values are larger than the previous filtering result, it is normal, otherwise it is regarded as inconsistent.2) Whether the data changes quickly, which is to judge the difference between the sampling value and the previous filtering result.Adjustment Principle1) When the two data changes are inconsistent, it means there is jitter. Clear the filtering coefficient to zero, and delete the new sampling value.2) When the data changes consistently, gradually increase the filtering coefficient to provide the weight of this sampling.3) When the data changes quickly (difference value> debounce count acceleration response threshold), the filtering coefficient should be increased quickly. Adjusting Filter Coefficient Process① Calculate the difference (absolute value) between the current sampling value and the last filtering result; Set the data change direction flag.② Two changes in the same direction?③ First order filter coefficient + coefficient increment (the maximum value is taken when the result is greater than the maximum value). Several Constant Parameters and Their Ranges1. Debounce counting acceleration response threshold is determined according to the actual situation.2. The maximum value of debounce count, which is generally 10.3. The increment of filtering coefficient range is 10~30.4. The maximum value of the filtering coefficient is generally 255.Before starting the first-order filtering program, open the adjustment filter coefficient program to adjust the coefficients in real time. Filtering Effect1. When the sampled data is accidentally interfered, the interference in the filtering result is completely filtered out.2. When the data oscillates within a range, the filtering result curve is very smooth, almost a straight line.3. When the sampling data has real changes, the filtering results can be followed up in a relatively timely manner.4. When the sampling data becomes stable, the filtering result gradually approaches and is finally equal to it.Finally, improve the algorithm. Taking into account the requirements of sensitivity and stability; and meanwhile, it does not consume too much RAM space. As long as a few constants are adjusted reasonably, the algorithm is more suitable for practical applications. Frequently Asked Questions about RC Low Pass Filter1. What is RC low pass filter?A low pass filter is a filter which passes low-frequency signals and blocks, or impedes, high-frequency signals. ... Low pass filters can be constructed using resistors with either capacitors or inductors. A low pass filter composed of a resistor and a capacitor is called a low pass RC filter. 2. Why RC circuit is low pass filter?Then by carefully selecting the correct resistor-capacitor combination, we can create a RC circuit that allows a range of frequencies below a certain value to pass through the circuit unaffected while any frequencies applied to the circuit above this cut-off point to be attenuated, creating what is commonly called a rc low pass fiter. 3. What is difference between RC low pass filter and RC high pass filter?Low pass filter is the type of frequency domain filter that is used for smoothing the image. It attenuates the high frequency components and preserves the low frequency components. High pass filter: ... It attenuates the low frequency components and preserves the high frequency components. 4. What is the transfer function of a low pass filter?Low Pass Filters and their Transfer FunctionsAs its name implies, a low pass filter is an electronic device that allows low frequency AC signals to pass a current through the filter circuit. The output from the filter circuit will be attenuated, depending on the frequency of the input signal. 5. How is low pass filter frequency calculated?The cut-off frequency or -3dB point, can be found using the standard formula, ƒc = 1/(2πRC). The phase angle of the output signal at ƒc and is -45o for a Low Pass Filter.

IntroductionThe modern automobile industry is developing very rapidly. Take car keys for example, the traditional mechanical keys are basically replaced now. Because our remote control keys and even smart keys are already very common. However, this also brings some troubles to many consumers-what should I do if the key is out of power or the battery is damaged? How to replace the battery? What type of battery should I choose?For example, in most cases, temperatures too high or too low still compromise their ability to store and release energy. Put simply, cold weather will decrease the lifespan of your battery because it will require charging more often. Here will give you some basic ideas of car key batteries comparison in modern life.CatalogIntroductionⅠ What Are CR Batteries?1.1 CR×××× Definition1.2 CR Button Battery ExamplesⅡ SummeryⅠ What Are CR Batteries?1.1 CR×××× DefinitionGenerally speaking, the batteries of car keys are button batteries, which have a relatively long service life. Conventionally, a battery can be used for more than 3 years. To replace the battery of the car key, you must buy the right model. Not all car keys use CR2032, while CR2450, CR2025, and CR2016 are also optional. Here, what models are CR2032 and CR2025? What does CR stand for in battery? According to IEC rules, in Lithium batteries, Chromium is also used in it that is why it's also called CR batteries. Most of the people related CR with the button or coin batteries but it's a chemical designation of Chromium.C-denotes Lithium Manganese Dioxide.R-after another letter denotes a round cell with the chemistry shown by the first letter.Digit-The next four digits indicate the size, the first two digits indicate the diameter, and the last two digits indicate the thickness.All the batteries who have this chemical substance in their batteries they can use this abbreviation CR.1.2 CR Button Battery Examples🚩CR2032 BatteryMax Size: 20.0×3.2mmNominal Capacity: 240mAhNominal Voltage: 3.0VOperating Temperature: -20°C ~+60°CRef.Weight: 3.0gCR2032 batteries is the most common battery coin providing long-lasting, reliable power for various devices. They are used to power small electronics devices such as calculators, wrist watches, various medical devices, fitness appliances, toys etc. As for CR2032 run time, that is, how long should a 2032 battery last? For example, a typical LED uses about 20mA and the capacity of a CR2032 Coin Cell is 200mAh. 🚩CR2016 BatteryMax Size: 20.0×1.6mmNominal Capacity: 90mAhNominal Voltage: 3.0VStandard Current: 0.1mAMax Continuous Current: 1.0mAMax Pulse Current: 15mARef.Weight: 1.8gCR2016 batteries are commonly used in calculators, digital watches, memory back-up, laser pens, car key remotes, calculator, toys, fitness appliances and medical devices like a clinical thermometer and a tensiometer. It has a proven track record for appliances where conventional batteries cannot be used. 🚩CR2025 BatteryMax Size: 20.0×2.5mmNominal Capacity: 170mAhNominal Voltage: 3.0VMax Continuous Current: 2.0mAMax Pulse Current: 20mARef.Weight: 2.5gCR2025 batteries provide long-lasting reliable power in various devices. This battery is frequently used in car key remotes, medical devices, digital watches, fitness devices and other electronics. 🚩CR1632 BatteryMax Size: 16.0×3.2mmNominal Capacity: 120mAhNominal Voltage: 3.0VMax Continuous Current: 1.0mAMax Pulse Current: 15mARef.Weight: 1.8gCR1632 batteries mainly used for low power consumption electronic products, generally its output current from 0.001mA to 5mA. For example, CR1632 batteries are often used in car key remotes, watches, toys and other electronic appliances. Also it provides long-lasting reliable power. Store in room temperature, ventilated, dry environment (humidity not more than 60%), having period of validity up to 2 years. 🚩CR2450 BatteryMax Size: 24.0×5.0mmNominal Capacity: 520mAhNominal Voltage: 3.0VOperating Temperature: -30°C ~+60°CMax Continuous Current: 3.0mAMax Pulse Current: 20mARef.Weight: 5.8gVery high weight-to-power ratioNo mercury addedHigh leak protectionCR2450 batteries have certain accomplishments for applications where traditions where traditional cannot be used. Use them for calculators, digital watches, laser pens, car keys, medical devices like a clinical thermometer and a tensionmeter and fitness appliances. Store in room temperature, ventilated, dry environment (humidity not more than 60%), having period of validity up to 3-5 years.🚩Recommended Readingcr2025 vs cr2032cr2016 vs cr2032Ⅱ SummeryThey are not rechargeable, and are all lithium primary batteries. That is, they are very similar to each other. The shelf life of lithium coin cells stored at normal room temperature and relative humidity is 10 years. If the manufacturing level is not high or the quality control is not good, their life will be greatly shortened. What’s more, if the use environment is ideal, their life span can reach 10 years or more. They are often used on computer motherboard CMOS batteries, memory functions or power-off protection modules, electronic scales, calculators, electronic dictionaries and other products, and can also be used on car remote control keys. With the requirements of new industries, there are also specially improved with very different capacities, mainly to improve their high-current output capabilities, such as those used in flashing lights or RF products.From the above, we can see the difference between them. As for interchangeable batteries, if you are a consumer, replace the battery with the same one that was originally intended, as the holder was designed to fit either one or the other.A derivative problem, what happens to old lithium batteries? Since they cannot be recharged, they has to be disposed of properly. For proper disposal of large numbers of lithium batteries at the same time, they can be disposed of by scattering them in different directions so that they will not touch one another. In short, you can't throw away lithium-ion batteries with your regular trash or even in your blue recycling bin. What you should do is dropping them off at a battery recycling center or battery drop-off, or requesting a battery pick-up through your local government's website. Frequently Asked Questions about Difference between Cr2032 and CR2025, CR2016, CR24501. Can I replace a CR2016 battery with a CR2032?They are not the same in thickness, the cr2016 is thinner then the cr2032 although if you stack two of the cr2016 batteries then it will then be the same thickness as the cr2032 battery and they both worked for the car stereo remote and key fob. That is, if it fits in the device's battery slot and makes a good electrical connection, a CR2016 can substitute for a CR2032. However, it will have less than half the CR2032's lifetime. 2. Can I use a CR2032 in place of a CR2025?2032 and 2025 are literally the dimensions of the battery. For as long as either fits in the battery compartment, the CR2025 and CR2032 may be used interchangeably with minimal effect although the CR2032 would probably last slightly longer simply because it has a higher capacity (mAh). 3. Are CR1632 and CR2032 interchangeable?The CR1632 battery is very similar to CR2032 or CR2025 but they are not interchangeable because of their dimensions. The name CR1632 indicates that the battery is 16mm wide and 3.2mm thick. It is rated for 3V and 130mAh capacity. 4. Is CR2450 the same as CR2032?CR2450 vs CR2032CR2450 is often compared with a very popular lithium 3.0 volts CR2032 battery. Output voltages of these batteries are the same for the same chemistry types. However, due to the larger volume of CR2450, it features a larger capacity - 600-620 mAh (CR2450) vs 210-230 mAh (CR2032). 5. What battery is equivalent to CR2032?

Ⅰ IntroductionThe Hall Effect is the most common method of measuring magnetic fields, and Hall Effect Sensors are widely used and have a wide range of applications in modern times. For example, they're used in cars as wheel speed sensors and crankshaft or camshaft position sensors. They're often used as switches, MEMS compasses, proximity sensors, and other applications. Now we'll take a look at a few of these sensors to see how they function, but first, let's define the Hall Effect. CatalogⅠ IntroductionⅡ What is Hall EffectⅢ What is a Hall Effect SensorⅣ How Does a Hall Effect Sensor WorkⅤ Hall Effect Sensor Types  5.1 Threshold  5.2 LinearⅥ Hall Effect Sensor Uses  6.1 Head-on Detection  6.2 Sideways DetectionⅦ Hall Effect Sensor Applications  7.1 Hall Effect Sensor in Rotary Applications  7.2 Hall Effect Sensor in Proximity Applications  7.3 Proximity Hall Effect Sensor Uses in RoboticsⅧ How to Test Hall Effect SensorsⅨ FAQ Ⅱ What is Hall EffectThe experiment that describes the Hall Effect is as follows: If we have a thin conductive plate like the one shown and apply current to it, the charge carriers will flow in a straight line from one side to the other.Now, if we apply a magnetic field near the plate, we can disrupt the charge carriers' straight flow due to a force known as the Lorentz Force. The electrons would deflect to one side of the plate, while the positive holes would deflect to the other. This means that if we now connect the other two sides with a meter, we can get a voltage that can be measured.As previously mentioned, the effect of obtaining a measurable voltage is known as the Hall Effect, after Edwin Hall, who discovered it in 1879.  Ⅲ What is a Hall Effect SensorA Hall Effect sensor detects changes in magnetic field power. This sensor opens up a wide range of possibilities for robotic sensor applications.They can be used in applications such as proximity, positioning, speed, and current sensing. They're usually used on pneumatic cylinders, where they're used to communicate the cylinder's position to a PLC or robotic controller.Automotive, personal electronics, and robotics are only a few of the industries that use Hall Effect sensors. Depending on the application, they have some advantages over other sensors. They are fully encased because they operate with a magnetic field, making them less vulnerable to damage from dirty or wet conditions. They are less likely than mechanical systems to wear out or skew readings after a large number of cycles. Hall Effect sensors are useful for a wide range of applications due to their reliability and longevity since they do not need physical contact to operate properly. They can provide more repeatability and accuracy than mechanical units because they do not physically interfere with the machinery or tooling.  Ⅳ How Does a Hall Effect Sensor WorkIt's best to start with the basics of the Hall Effect to comprehend a Hall Effect sensor. As current flows through a conductor in the presence of a magnetic field, the electrons are pushed to one side of the conductor by the magnetic field. The Hall Effect can be used to measure electric current in conductors that are built with certain parameters in view. The voltage across a flat metallic conductor, for example, reveals the Hall Effect much better than the voltage across around one.The electrons moving over the conductor are forced to one side when a magnetic field is applied to the flat plate. Since the sum of deflection can be calculated, the apparatus has a wide range of applications. A flat plate conductor is used to calculate magnetic strength in a Hall Effect sensor. When a magnet gets close to the sensor, the sensor detects it and sends the information to a controller. The charge across the plate is shifted to one side while the magnet is near the sensor, producing a positive charge on one side and a negative charge on the other. The voltage difference between the two sides of the plate is determined, and it can be used to calculate magnetic strength or sensor proximity.  Ⅴ Hall Effect Sensor TypesHall Effect Sensors come in two basic types:5.1 ThresholdWhen the field strength reaches a certain amplitude and/or polarity, the threshold (also known as digital or on-off) produces a constant hall voltage. There are several different threshold device configurations, such as latching devices that turn on when a positive field strength reaches the threshold but only turn off when a negative field of the same strength reaches the threshold, devices that turn on when only a positive field reaches the threshold but are off otherwise, and devices that turn on when either a positive or negative field reaches the threshold. Thresholds can also be programmed in some computers. 5.2 LinearLinear (analog output sensor) generated a hall voltage proportional to the magnetic field strength around it. The polarity of the voltage swing is determined by the direction of the surrounding magnetic field. When expressive movements must be sensed as small changes in position, linear devices are more commonly used in musical applications. Ⅵ Hall Effect Sensor UsesHall effect sensors are powered by a magnetic field, and in many applications, a single permanent magnet connected to a moving shaft or device may control the device. There are many different forms of magnet sensing motions, including "Head-on", "Sideways", "Push-pull", and "Push-push" among others. To ensure optimum sensitivity, magnetic lines of flux must always be perpendicular to the sensing region of the system and of the right polarity, regardless of the configuration. High field strength magnets with a significant change in field strength for the necessary movement are also required to ensure linearity. There are several ways to detect a magnetic field, and two of the most common sensing configurations using a single magnet are shown below: Head-on detection and sideways detection are two types of detection. 6.1 Head-on DetectionThe magnetic field must be perpendicular to the hall effect sensing system and approach the sensor straight on towards the active face for "head-on detection" as the name suggests. In a way, it's a "front-on" approach. This direct approach produces an output signal, VH, which in linear devices reflects the magnetic field power, or magnetic flux density, as a function of distance from the hall effect sensor. The output voltage increases as the magnetic field gets closer and hence stronger, and vice versa. Positive and negative magnetic fields can also be differentiated by linear instruments. For indicating positional detection, non-linear devices can be made to trigger the output "ON" at a pre-set air gap distance away from the magnet. 6.2 Sideways Detection"Sideways detection" is the second sensing configuration. This necessitates moving the magnet sideways across the face of the Hall effect element. For example, counting rotational magnets or measuring the speed of rotation of motors, sideways or slide-by detection is useful for detecting the presence of a magnetic field as it travels across the face of the Hall element within a fixed air gap distance. A linear output voltage representing both a positive and negative output can be generated depending on the direction of the magnetic field as it passes by the sensor's zero-field centerline. This enables the identification of directional movement in both vertical and horizontal directions. Hall Effect Sensors have a wide range of applications, especially as proximity sensors. Where the environmental factors include water, vibration, dirt, or oil, such as in automotive applications, they can be used instead of optical and light sensors. Present sensing can also be done with Hall effect instruments.A circular electromagnetic field is formed around a conductor when a current passes through it, as we learned in previous tutorials. Electrical currents ranging from a few milliamps to thousands of amperes can be calculated from the induced magnetic field by placing the Hall sensor next to the conductor without the use of large or expensive transformers and coils. Hall effect sensors can be used to detect ferromagnetic materials such as iron and steel, in addition to detecting the presence or absence of magnets and magnetic fields, by putting a small permanent "biasing" magnet behind the active region of the device. Any shift or disruption to this magnetic field caused by the introduction of a ferrous material can be detected with sensitivities as low as mV/G. Depending on the type of device, whether digital or linear, there are a variety of ways to connect Hall effect sensors to electrical and electronic circuits. The use of a Light Emitting Diode, as shown below, is a very simple and easy-to-build example. Hall effect sensors can be used in a variety of ways due to the different magnetic movements. In both industrial and domestic environments, the most common application for these instruments is to measure objects' presence, position, and proximity. Current sensors, pressure sensors, and fluid flow sensors are all popular applications for Hall effect sensors in industrial and manufacturing processes. In current transformers, Hall effect sensors are an inexpensive, contactless way to measure DC magnetic flux.  Ⅶ Hall Effect Sensor Applications7.1 Hall Effect Sensor in Rotary ApplicationsSpeed sensors operate by counting the number of times a shaft or disk rotates in a given amount of time. A disk attached to the motor shaft rotates next to the Hall Effect sensor and has magnets on its perimeter. The state of the sensor is shifted as the magnets move through it. Based on this data, the sensor calculates the revolutions. For example, if the disk or shaft has four magnets, the sensor can switch states four times per revolution.This enables the sensor to measure the RPM based on the known parameter that four pulses per revolution will occur. This technology is used in brushless DC motors to track speed and detect shaft position. This enables them to run at specific RPM ranges while still allowing them to change the motor speed at any time. This makes controlling the motors a lot easier. It also allows them to monitor the location of the shaft on the motor, making them much more flexible in the robotics industry than motors without Hall Effect sensors. 7.2 Hall Effect Sensor in Proximity ApplicationsBased on a magnetic field, Hall Effect sensors can detect proximity. If the magnetic field strength is constant and defined, the position of the sensor in relation to the magnet can be determined. When a magnet moves into its range, the sensor changes states and alerts the controller. Proximity Hall Effect sensors can be used in a variety of ways. Robotic tooling, robotic grippers, pneumatics, and a variety of other non-robotic applications use them.7.3 Proximity Hall Effect Sensor Uses in RoboticsProximity Hall effect sensors can also be used in robotics. They're good for detecting magnetic strength and magnet proximity. Hall Effect sensors may be used to meet a variety of safety requirements. They are often used in tooling to provide clamp confirmation to the controlling device. Clamp confirmation locks the cell's operation until all sections are fully clamped, allowing it to function safely. Magnets embedded in the tooling that fall within the sensing range of the Hall Effect sensor when properly clamped normally dictate part confirmation. The robotic controller or PLC knows the cell is safe to operate when all sensors display a signal. In the robotics industry, Hall Effect sensors are extremely useful. For sensing changes in the cell, most robotic cells use a Hall Effect sensor. They are used to read the speed and position of DC brushless motors. They are used in pneumatic cylinders to determine if the cylinder is extended or retracted. They can also be used to keep staff healthy by notifying the controlling body of tooling clamp confirmation. Without Hall Effect sensors, the robotics industry will be very different.  Ⅷ How to Test Hall Effect SensorsThe camshaft and crankshaft position sensors are Hall effect sensors that control the camshaft and crankshaft position, respectively. In front of the sensor, a small magnet passes. The output voltage increases as the magnet get closer to the sensor. The voltage drops as the magnet moves away from the sensor. To assess shaft position, the electronic control module tracks these sensor outputs. The ECM can maintain precise engine control thanks to the camshaft and crankshaft position sensors, as well as other electrical sensors, solenoids, and injectors. Understand the basics of Hall effect sensors will aid you in properly testing a questionable sensor. • Step 1Remove the sensor from the engine block. Remove any oil, dirt, or metal shavings from the sensor tip. • Step 2Examine the engine's schematic for the camshaft sensor or crankshaft signal to the ECM. The signal wire from the ECM should be removed. Connect the signal wire to one end of the jumper wire. Connect the jumper wire's other end to the optimistic probe's edge. Connect the negative probe to stable chassis ground. Connect the negative probe to the chassis ground with a jumper and alligator clips if necessary. To test DC volts, switch the electric voltmeter. Turn the key switch to "On". Ideally, the voltage should be about 0 volts. Slowly rotate the magnet perpendicular to the sensor's front. When the magnet approaches the sensor, the voltage should rise, and as it moves away, the voltage should fall. There is a problem with the sensor or the sensor's connections if the voltage does not change. Ⅸ FAQ1. How does a Hall effect sensor work?Using semiconductors (such as silicon), Hall effect sensors work by measuring the changing voltage when the device is placed in a magnetic field. In other words, once a Hall effect sensor detects that it is now in a magnetic field, it can sense the position of objects. 2. What triggers a Hall effect device?Hall effect sensors are activated by a magnetic field and in many applications, the device can be operated by a single permanent magnet attached to a moving shaft or device. There are many different types of magnet movements, such as ‘Head-on’, ‘Sideways’, ‘Push-pull’ or ‘Push-push’ etc sensing movements. 3. What is the use of a hall effect sensor?Hall effect sensors are commonly used to time the speed of wheels and shafts, such as for internal combustion engine ignition timing, tachometers and anti-lock braking systems. They are used in brushless DC electric motors to detect the position of the permanent magnet. 4. What is the principle of the Hall effect?The Hall Effect principle states that when a current-carrying conductor or a semiconductor is introduced to a perpendicular magnetic field, a voltage can be measured at the right angle to the current path. 5. How sensitive is a Hall effect sensor?These ratiometric devices have a sensitivity of 5 mV/gauss and 2.5 mV/ gauss, respectively, an operating temperature range of -40°C to +150°C, and are temperature compensated over their full operating range. 6. What is the difference between a Hall effect sensor and an inductive sensor?Inductive sensors detect metallic objects and hall effect sensors detect the presence of a magnetic field. 7. What is the origin of the Hall effect?The history of the Hall effect begins in 1879 when Edwin H. Hall discovered that a small transverse voltage appeared across a current-carrying thin metal strip in an applied magnetic field. 8. How can you tell if a Hall sensor is bad?Loss of power, loud noise and the feeling that the motor is somehow blocked are often signs that either the controller is dead or that you may have issues with the hall sensors inside the motor. 9. What is inside a Hall effect sensor?The Hall effect sensor is a thin sliver of semiconductor material just like the chip inside a micro or RAM devise. It works on the electromagnetism principle. When you move a magnet close enough to the sensor generates a small voltage. This goes to an amplifier which boosts the voltage high enough to be used by other electronic devices. The best example is the wheel speed sensor. A small magnet is attached to the inside of a car wheel. Every time the magnet moves past the sensor that is one rotation of the wheel. The information is passed to the speedometer and odometer unit where it is displayed to the driver. 10. What is a hall effect sensor for on a vehicle?A hall effect sensor operates by a magnetic field and can also be referred to as a crank position sensor. It checks the crankshaft position for the engine to fire the spark plugs. If it is bad, the engine might stall and would not start without the signal from the Hall effect sensor. Hall effect sensors can also be used to determine speed, distance, or engine crankshaft position and camshaft position. All hall effect sensors have different electronics internally with different program measurements and are not interchangeable.

IntroductionA p-n junction is an interface or a boundary between n-type and p-type semiconductor materials, inside a semiconductor. One of the crucial keys to solid state electronics is the nature of the P-N junction. For example, a PN Junction Diode is one of the simplest semiconductor devices around, and which has the characteristic of passing current in only one direction only. And the p-side or the positive side of the semiconductor has an excess of holes and the n-side or the negative side has an excess of electrons. Why pn junction exists? and How does it work? What is p-n junction diode?PN Junction IntroductionCatalogIntroductionIntroductionⅠ PN Junction Basic1.1 PN Semiconductor1.2 PN Junction ReviewⅡ PN Junction Characteristic2.1 Unidirectional Conductivity2.2 Reverse Breakdown2.3 Volt-Ampere Characteristic2.4 Capacitance CharacteristicⅢ Typical Example: Transistor PN JunctionⅠ PN Junction Basic1.1 PN SemiconductorN-type SemiconductorIn silicon crystal (or germanium crystal) doped with a small amount of impurity phosphorus element (or antimony element), since semiconductor atoms (such as silicon atoms) are replaced by impurity atoms, among the five outer electrons in the outer layer of phosphorus atoms four of them form covalent bonds with the surrounding atoms, and the extra electron is almost unbound and becomes a free electron more easily. Therefore, the N-type semiconductor has become a semiconductor with a higher concentration of electrons, and its conductivity is mainly due to the conduction of free electrons.P-type SemiconductorIn silicon crystal (or germanium crystal) doped with a small amount of impurity boron element (or indium element), since semiconductor atoms (such as silicon atoms) are replaced by impurity atoms, the three outer electrons in the outer layer of boron atoms and a semiconductor atom form a covalent bond, at this time, a "hole" is generated. This hole may attract bound electrons to "fill", making the boron atom a negatively charged ion. In this way, this type of semiconductor has a higher concentration of "holes" ("corresponding to" positive charges) and becomes a substance capable of conducting electricity.1.2 PN Junction ReviewP-N junction is formed by joining n-type and p-type semiconductor materials, which is a two terminal device that allows electric current in one direction and blocks electric current in another direction.Figure 1. How is PN Junction FormedOn a silicon wafer, different doping processes are used to form an N-type semiconductor on one side and a P-type semiconductor on the other side. We call the area near the interface of the two semiconductors a PN junction.After the P-type semiconductor and the N-type semiconductor are combined, since the free electrons in the N-type region are more and the holes are less, the concentration difference between electrons and holes appears at their junction. Due to the difference in the concentration of free electrons and holes, some electrons will diffuse from the N-type region to the P-type region, and some holes will diffuse from the P-type region to the N-type region. As a result of their diffusion, the P region loses holes, leaving negatively charged impurity ions, and the N region loses electrons, leaving positively charged impurity ions. The ions in the semiconductor cannot move arbitrarily in an open circuit, so they do not participate in conduction. These immovable charged particles form a space charge zone near the interface between the P and N zones. The thickness of the space charge zone is related to the concentration of dopants.After the space charge region is formed, due to the interaction between the positive and negative charges, an internal electric field is formed in the space charge region, the direction of which is from the positively charged N region to the negatively charged P region. Obviously, the direction of this electric field is opposite to the direction of carrier diffusion, which used to prevent diffusion.On the other hand, this electric field will cause the minority carrier holes in the N region to drift to the P region, and the minority carrier electrons in the P region to drift to the N region. The direction of the drift movement is just opposite to the diffusion movement. The holes drifting from the N region to the P region supplement the holes lost in the P region on the original interface, and the electrons drifting from the P region to the N region supplement the electrons lost in the N region on the original interface, which makes the electric charge is reduced and the internal electric field is weakened. Therefore, the result of drift motion is to narrow the space charge region and strengthen the diffusion motion.Finally, the diffusion of multiple carriers and the drift of minority carriers reach a dynamic balance. On both sides of the junction surface of the P-type semiconductor and the N-type semiconductor, a thin ion layer is left. The charge area formed by this thin ion layer is called a PN junction. The direction of the internal electric field of the PN junction points from the N to the P. It is also called the depletion layer, because lack of electrons.Figure 2. PN Junction Depletion RegionⅡ PN Junction Characteristic2.1 Unidirectional Conductivity(1) The PN junction is turned on when the forward voltage is applied.If the positive pole of the power supply is connected to the P area and the negative pole is connected to the N area, a part of the applied forward voltage is in the PN junction area, at this time, the PN junction is in a forward bias. The current flows from the P to the N, and the holes and electrons move to the interface, which narrows the space charge area. In addition, the current can pass smoothly. Its direction is opposite to the direction of the electric field in the PN junction, which weakens the internal electric field. As a result, the resistance of the internal electric field to the diffusion movement of the multitons weakens, and the diffusion current increases. The diffusion current is much larger than the drift current, and the influence of the drift current can be ignored, and the PN junction is in low resistance.(2) PN junction is cut off when reverse voltage is applied.If the positive pole of the power supply is connected to the N zone, the negative pole is connected to the P zone, and a part of the applied reverse voltage applies in the PN junction zone, and it is in reverse bias. Then the holes and electrons move away from the interface, which widens the space charge area, and the current cannot flow. The direction is the same as the direction of the electric field in the PN junction, which strengthens the internal electric field. The resistance of the internal electric field to the multiton diffusion movement is enhanced, and the diffusion current is greatly reduced. At this time, the drift current formed by the minority carriers in the PN junction region under the action of the internal electric field is greater than the diffusion current. The diffusion current can be ignored, and the PN junction exhibits high resistance.2.2 Reverse BreakdownWhen a reverse voltage is applied to the PN junction, the space charge region becomes wider and the electric field in the region strengthens. When the reverse voltage increases to a certain level, the reverse current will suddenly increase. If the external circuit cannot limit the current, the current will be so large that it will burn the PN junction. At this time, it is called the breakdown voltage. There are two basic breakdown ways, namely tunnel breakdown (also called Zener breakdown) and avalanche breakdown. The former has a breakdown voltage of less than 6V and has a negative temperature coefficient, and the latter has a breakdown voltage of greater than 6V and a positive temperature coefficient.2.3 Volt-Ampere CharacteristicThe volt-ampere characteristics of the PN junction are shown in the Figure 3, which visually shows the unidirectional conductivity.Figure 3. Volt-Ampere Curve of the PN JunctionThe volt-ampere characteristic shows by Where iD is the current passing through the PN junction, VD is the applied voltage at both ends of the PN junction, and VT is the voltage equivalent of temperature.2.4 Capacitance CharacteristicWhen a reverse voltage is applied to the PN junction, the positive and negative charges in the space charge region constitute a capacitive device. Its capacitance changes with the applied voltage, mainly including barrier capacitance (CB) and diffusion capacitance (CD). Both of them are non-linear capacitors. Ⅲ Typical Example: Transistor PN JunctionTransistors are one of the basic building blocks of modern electronics. In the diode tutorials we saw that simple diodes are made up from two pieces of semiconductor material to form a simple pn-junction. While the transistor is a three terminal solid state device which is formed by connecting two diodes back to back. Hence it has got two PN junctions.Transistor NPN-Type and PNP-Type JunctionsTransistor Working StateThe transistor works like an electronic switch. It can turn a current ON and OFF. The basic idea behind a transistor is that it lets you control the flow of current through one channel by varying the intensity of a much smaller current that's flowing through a second channel.1) Cut-off State (C): The base current is zero.2) Amplified State (A): The transmitter junction is forward biased (that is, the voltage direction is P->N), and the collector junction is reverse biased.3) Saturation State (S): Both the emitter junction and the collector junction are forward biased.Working StateNPN-Type TransistorPNP-Type TransistorVb<Ve (C)Vc>Vb>Ve (A)Vb>Ve Vb>Vc (S)Vb>Ve (C)Vc<Vb<Ve (A)Vb<Ve Vb<Vc (S)In Figure (a), when there is no voltage input at b of the NPN transistor, no current flows between c and e, and the triode is in the cut-off state.In Figure (b), when a positive voltage is input to b of the NPN transistor, the negative electrons in the N region of e are attracted by the positrons of P region in b. Due to the effect of the power plant, and they rush (diffuse) to the base region, however, only part of the negative electrons collide with the positive electrons (recombination) to generate the base current, and the other part of the negative electrons gather near the collector junction. The negative electrons gathered in the collector junction pass through (drift) the collector junction due to the action of the electric field. After reaching the collector area, it collides with the positrons gathered in c (N-type semiconductor terminal) to generate a collector current.It can be seen from this that the greater the base current, the greater the collector current. That is, when a small current is input to the collector, a large current can be obtained by the collector, and now the transistor is in an amplified state.It should be noted that when the base current reaches a certain level, the collector current no longer rises. At this time, the transistor loses its current amplification effect, and the voltage between the collector and the emitter is very small. The collector and emitter are equivalent to the on-state of the switch. At this moment, the transistor is in a saturated state.The working principle of the PNP transistor is the same as that of the NPN transistor, except that the direction of the bias voltage and the current are opposite, and the roles of electrons and holes are reversed. The PNP transistor uses Veb to control the positrons incident on the collector area from the emitter area through the base area, while the NPN transistor uses Vbe to control the negative electrons that enter the collector area from the emitter area through the base area.In addition, in a low-power design, the transistor control circuit will have a certain impact on the circuit. No matter it is NPN or PNP, there will be leakage current in the PN junction of the transistor. When the I/O controls the base voltage, in order to stabilize the base voltage, a pull-down resistor is generally added to the base of the NPN switch circuit. In the design of the PNP switch circuit, a pull-down resistor is added to the base. The pull-up and pull-down resistors are selected according to the control chip, transistor and circuit voltage. Frequently Asked Questions about PN Junctions Formed1. What is PN junction and how it is formed?P-n junctions are formed by joining n-type and p-type semiconductor materials, as shown below. ... However, in a p-n junction, when the electrons and holes move to the other side of the junction, they leave behind exposed charges on dopant atom sites, which are fixed in the crystal lattice and are unable to move. 2. What is p-type and n-type?In silicon doping, there are two types of impurities: n-type and p-type. In n-type doping, arsenic or phosphorus is added in small quantities to the silicon. ... In p-type doping, boron or gallium is used as the dopant. These elements each have three electrons in their outer orbitals. 3. What is a PN junction diode?A PN Junction Diode is one of the simplest semiconductor devices around, and which has the characteristic of passing current in only one direction only. ... By applying a negative voltage (reverse bias) results in the free charges being pulled away from the junction resulting in the depletion layer width being increased. 4. What happens in a PN junction?A forward-biased PN junction conducts a current once the barrier voltage is overcome. The external applied potential forces majority carriers toward the junction where recombination takes place, allowing current flow. A reverse-biased PN junction conducts almost no current. 5. What is a PN junction used for?A p-n junction diode is a two terminal device that allows electric current in one direction and blocks electric current in another direction. In forward bias condition, the diode allows electric current whereas in reverse bias condition, the diode does not allow electric current.

CatalogⅠ What is a Tantalum CapacitorⅡ Construction and Properties of Tantalum CapacitorⅢ Characteristics of Tantalum Capacitor  3.1 General Characteristic  3.2 Polarity  3.3 Failure Mode of Tantalum CapacitorⅣ Tantalum Capacitor Classification  4.1 Leaded Tantalum Capacitors  4.2 SMD Tantalum CapacitorsⅤ Applications for Tantalum CapacitorⅥ Difference Between Tantalum and Ceramic CapacitorⅦ FAQ Ⅰ What is a Tantalum CapacitorTantalum capacitors have a tantalum anode and are electrolytic capacitors. They're polarized capacitors that have excellent frequency and stability. Electrolytic capacitors with tantalum as a component are known as tantalum capacitors. They're made of tantalum metal, which serves as an anode, with a layer of oxide acting as a dielectric and a conductive cathode surrounding it.Tantalum is used to create a very thin dielectric layer. As a result, the capacitance value per volume is higher, the frequency characteristics are superior to many other types of capacitors, and the capacitor has excellent long-term stability. Tantalum capacitors are usually polarized, which means they can only be connected to a DC supply if the terminal polarity is maintained. The disadvantage of using tantalum capacitors is that they have an unfavorable failure mode, which can result in thermal runaways, fires, and minor explosions. This can be avoided by using external failsafe devices such as current limiters or thermal fuses. Tantalum capacitors can now be used in a wide range of circuits, including computers, automobiles, cell phones, and other electronic devices, most commonly surface-mounted devices (SMD). These surface-mount tantalum capacitors take up significantly less space on the printed circuit board, allowing for higher packing densities. It's worth noting that, like resistors, there are both fixed and variable capacitors. Capacitors with fixed values are classified as either non-polarized or polarized capacitors, depending on their polarity. The three most common capacitor types are represented by electric symbols in the figure below.Tantalum capacitor-capacitor symbols Ⅱ Construction and Properties of Tantalum CapacitorTantalum (Ta) is a silver-gray metal with the atomic number 73. When looking at a cross-sectional view of a tantalum capacitor, such as a standard SMD tantalum electrolytic chip capacitor with solid electrolyte shown in the Figure below, the positive (anode) terminal is tantalum powder pressed and sintered into a pallet. The dielectric is formed by an insulating oxide layer covering the positive (anode) terminal, and the negative (cathode) terminal is formed by a solid manganese dioxide electrolyte. Tantalum capacitor-construction of tantalum capacitor In the case of solid tantalum capacitors, the electrolyte is added to the anode through pyrolysis. To create a manganese dioxide coat, solid tantalum capacitors are dipped in a special solution and baked in an oven. The procedure is repeated until the pellet has a dense coating on both internal and external surfaces. Finally, to ensure a strong cathode connection, the pellet used in solid tantalum capacitors is dipped in graphite and silver. Wet tantalum capacitors, unlike solid tantalum capacitors, use a liquid electrolyte. The anode is dipped into a liquid electrolyte inside an enclosure after it has been sintered and a dielectric layer has been grown. In wet tantalum capacitors, the enclosure and electrolyte serve as the cathode. Tantalum capacitors have a high capacitance per volume and weight due to their thin, high permittivity dielectric sheet, which sets them apart from other electrolytic capacitors. Tantalum electrolytic capacitors are also ideal for passing or bypassing low-frequency signals and storing significant quantities of electric energy due to their large capacitance. Ⅲ Characteristics of Tantalum Capacitor3.1 General CharacteristicTantalum capacitors have capacitance values ranging from 1nF to 72mF and are significantly smaller than aluminum electrolytic capacitors of the same capacitance. Tantalum capacitors have voltage ratings ranging from 2V to more than 500V. They have a ten-fold lower equivalent series resistance (ESR) than aluminum electrolytic capacitors, allowing for higher currents to pass through the capacitor while generating less heat. As compared to aluminum electrolytic capacitors, tantalum capacitors are very stable over time and their capacitance does not change significantly with age. When handled properly, they are extremely dependable, and their shelf life is nearly limitless.3.2 PolarityTantalum electrolytic capacitors have a very high polarization. Although polarized aluminum electrolytic capacitors can survive a brief reverse voltage, tantalum capacitors are extremely sensitive to reverse polarization. When a voltage of the opposite polarity is applied, the dielectric oxide breaks down, resulting in a short circuit. This short circuit could lead to thermal runaway and the capacitor's destruction in the future. In comparison to aluminum electrolytic capacitors, which have their negative terminal marked on the casing, tantalum capacitors typically have their positive terminal marked.3.3 Failure Mode of Tantalum CapacitorAccording to a paper published by ASM International, the Tantalum capacitor failure mode is divided into three major groups. • High Leakage/ShortHigh leakage currents may result from applying reverse voltage, which is common during troubleshooting, malfunctions, and/or bench testing. Since the hotspots formed during crystallization heat the cathode, tantalum capacitors with crystallization cause short circuit failure.　　• High Equivalent Series Resistance (ESR)When a capacitor is exposed to board mounting, pick-and-place, reflow, and operation lifetime, the mechanical/thermomechanical has a significant impact on its ESR. External and/or internal relations are often harmed as a result of this form of stress, resulting in a high ESR. • Low Capacitance/OpenThe failure is uncommon since the capacitance of a Tantalum capacitor does not shift under normal operating conditions. A Tantalum capacitor's lower capacitance in any application may indicate a shorted capacitor, while an open failure can be caused by a damaged positive lead and wire link. Tantalum capacitors, as we all know, have a potentially dangerous failure mode. The tantalum anode may come into contact with the manganese dioxide cathode during voltage spikes, and if the energy of the spike is adequate, a chemical reaction may start. This chemical reaction generates heat and is self-sustaining, as well as the possibility of smoke and flame. External failsafe circuitry, such as current limiters and thermal fuses, should be used in combination with tantalum capacitors to avoid thermal runaway.  Ⅳ Tantalum Capacitor Classification4.1 Leaded Tantalum CapacitorsTo avoid damage, leaded tantalum capacitors are usually packaged in a small epoxy box. Tantalum bead capacitors are the name given to them because of their shape. Although a color-coding scheme was common at one time and some capacitors still use it, the capacitor markings are usually written directly onto the encapsulation as figures.Leaded tantalum capacitors 4.2 SMD Tantalum CapacitorsTantalum capacitors with a surface mount are commonly used in modern electronics. When designed with enough margins, they provide dependable service and allow for high capacitance values to be achieved in the small package sizes needed for modern equipment. Due to their inability to withstand the temperatures needed for soldering, aluminum electrolytes were not initially available in surface-mount packages. As a result, tantalum capacitors that could withstand the soldering process were nearly the only choice for high-value capacitors in surface-mount assemblies. Despite the availability of SMD electrolytic, tantalum remains the capacitor of choice for SMD due to its excellent cost, size, and performance parameters.SMD tantalum capacitor • SMD Tantalum Capacitor MarkingsSMD tantalum capacitors usually have three numbers on their markings. The major figures are the first two, and the multiplier is the third. Values are in picofarads. As a result, the SMD tantalum capacitor's value is 47 x 105pF, which equals 4.7F.As seen in the illustration below, values are often marked more directly. The markings indicate the value.SMD tantalum capacitor markings Ⅴ Applications of Tantalum CapacitorTantalum capacitors have many advantages and are used in a variety of applications, including modern electronics, where they provide higher stability over a wide range of temperatures and frequencies, long-term reliability, and record-high volumetric efficiency. Tantalum capacitors are used in applications because of their low leakage current, high capacity, and long-term stability and reliability. They're used in sample and hold circuits, for example, where a low leakage current is needed to achieve a long hold duration. Due to their small size and long-term reliability, they are often widely used for power supply filtering on computer motherboards and mobile phones, most commonly in surface-mount form.Applications of tantalum capacitorsMilitary standards (MIL-SPEC) tantalum capacitors are also available, with tighter tolerances and a wider operating temperature range. Since they do not dry out or change capacitance over time, they are a common substitute for aluminum electrolytic in military applications. Tantalum is also used in medical electronics because of its high stability. Tantalum capacitors are often used in audio amplifiers where stability is important. A tantalum capacitor is a complex component used in cardio implants to detect irregular heartbeats and deliver an electric countershock in a few seconds. Medical, telecommunications, aerospace, military, automotive, and computers are only a few of the industries that use this capacitor. Ⅵ Difference Between Tantalum and Ceramic CapacitorTantalum capacitors are used in a wide range of circuits, although they usually need an external failsafe system to prevent issues caused by their failure mode. PCs, laptops, medical equipment, audio amplifiers, automotive circuitry, mobile phones, and other surface-mounted devices are only a few examples (SMD). Tantalum electrolytic is a common alternative to aluminum electrolytic in military applications because it does not dry out or change capacitance over time. Ceramic capacitors are used in a wide range of applications, the most popular of which are personal electronic devices. MLCCs are the most widely used capacitors, accounting for around 1 billion electronic devices a year. Printed circuit boards (PCBs), induction furnaces, DC-DC converters, and power circuit breakers are some examples of applications. Since ceramic capacitors are non-polarized and come in a wide range of capacitances, voltage ratings, and sizes, they are often used as general-purpose capacitors. Tantalum Capacitors vs Ceramic CapacitorsWhile tantalum and ceramic capacitors have similar functions, their construction methods, materials, and performance are vastly different. Tantalum and ceramic capacitors vary in a few main ways when it comes to performance: • AgingWhen it comes to capacitors, aging refers to a logarithmic drop in capacitance over time. Tantalum capacitors do not age, while ceramic capacitors do. There is no known wear mechanism for tantalum capacitors. • PolarizationThe majority of tantalum capacitors are polarized. This means they can only be linked to a DC power source while maintaining proper terminal polarity. Non-polarized ceramic capacitors, on the other hand, can be safely connected to an AC source. Ceramic capacitors have a higher frequency response because they are not polarized. • Temperature ResponseTantalum capacitors have a linear capacitance change when exposed to temperature changes, whereas ceramic capacitors have a non-linear response. On the other hand, Ceramic capacitors can be made to trend linearly by narrowing the operating temperature ranges and taking temperature response into account during the design phase. • Voltage ResponseTantalum capacitors have clear capacitance changes as a function of applied voltage, whereas ceramic capacitors do not. The permittivity of the dielectric shrinks inside the ceramic capacitor in response to higher applied voltages, causing capacitance changes. While most ceramic capacitor capacitance changes are linear and easily accounted for, some higher permittivity dielectrics can lose up to 70% of their initial capacitance when operated at rated voltage.  Ⅶ FAQ1. What are the advantages and disadvantages of the tantalum capacitor?The list of the advantages and disadvantages of a solid tantalum capacitor includes the followingThe advantages are Long life, high-temperature resistance, excellent performance, high accuracy, efficiency in filtering high-frequency harmonics.The disadvantages are: Having a very thin oxide layer that is not robust, cannot withstand voltage above limits, low ripple current rating. 2. When to use a tantalum capacitor?When you need maximum capacitance in a small space like decoupling next to a microchip, excellent stability over a range of temperatures or voltages, and you are aware of their unique characteristics so they can be designed properly and not risk your system with a fiery failure. 3. What is surge voltage in terms of the tantalum capacitor?A surge voltage is the highest voltage that can be applied to a capacitor for a shorter period in circuits that has minimum series resistance. 4. What is the difference between tantalum and electrolytic capacitors?Electrolytic capacitors made with aluminum (or aluminum) are generally lower priced than those made with tantalum. Tantalum capacitors have higher capacitance per volume. Capacitors made with tantalum can be either polar and non-polar though the polarized form is more common. 5. Why do tantalum capacitors fail?A transient voltage or a current spike applied to tantalum electrolytic capacitors with solid manganese dioxide electrolyte can cause some tantalum capacitors to fail and may directly lead to a short. 6. How long do tantalum capacitors last?The capacitance stability achieved by polymer tantalum capacitors exceeds that of MLCCs over time, temperature and voltage. Whilst MLCCs are susceptible to aging, polymer tantalums achieve long-term stability over an operational lifetime of 20 years. 7. Are all tantalum capacitors polarized?Tantalum capacitors are inherently polarized components. Reverse voltage can destroy the capacitor. Non-polar or bipolar tantalum capacitors are made by effectively connecting two polarized capacitors in series, with the anodes oriented in opposite directions. 8. What is a tantalum capacitor used for?Applications using tantalum capacitors take advantage of their low leakage current, high capacity and long-term stability and reliability. For example, they are used in sample and hold circuits that rely on low leakage current to achieve long hold duration. 9. Can I replace a tantalum capacitor with an electrolytic?A tantalum capacitor is also a type of electrolytic capacitor, however, due to low leakage, they are more accurate and reliable than the cylindrical electrolytic capacitor variants. If the leakage factor is not too critical then you can easily replace a tantalum capacitor with the other regular electrolytic capacitor. 10. What is a wet tantalum capacitor?Wet tantalum capacitors are passive devices that provide capacitive reactance to circuits. They are electrolytic capacitors with a wet electrolyte, an anode and a cathode. They are used over other capacitor types due to superior characteristics including volumetric efficiency, high reliability, electrical stability over a wide temperature range and long service life. Wet tantalum capacitor technology is best suited for applications such as military, aerospace, satellites and heavy industrial application fields.