The Kynix Components

The 6N137 is a single channel 10 Mbd optocoupler utilizing a high efficient input LED coupled with an integrated optical photodiode IC detector. The detector has an open drain NMOS-transistor output, providing less leakage compared to an open collector Schottky clamped transistor output.Catalog6N137 Pin Configuration6N137 Features6N137 CAD Models6N137 ApplicationsWhere to Use 6N137 Optocoupler?How to Use 6N137 Optocoupler?6N137 Equivalents6N137 Package Outline6N137 Popularity by Region6N137 Market Price Analysis6N137 ManufacturerComponent DatasheetOrdering & Quantity6N137 Pin ConfigurationPin NoPin NameDescription1NCNo Connection - Cannot be used2Anode (A)Anode pin of the IR LED. Connected to logic input3Cathode (C)Cathode pin of the IR LED4NCNo Connection - Cannot be used5GroundGround pin of the IC6Output (VO)The isolated Output pin of the Optocoupler7Enable (VE)By default, it is enabled through a pull-up resistor.8VccPowers the IC6N137 FeaturesChoice of CMR performance of 15 kV/µs, 5 kV/µs, and 100 V/µsHigh speed: 10 Mbd typical+ 5 V CMOS compatibilityPure tin leadsGuaranteed AC and DC performance over temperature: - 40 °C to + 100 °C temperature rangeMeets IEC 60068-2-42 (SO2) and IEC 60068-2-43 (H2S) requirementsLow input current capability: 5 mALead (Pb)-free componentThe component in accordance to RoHS 2002/95/EC and WEEE 2002/96/EC6N137 CAD ModelsPart SymbolFootprint3D Model6N137 ApplicationsMicroprocessor system interfacePLC, ATE input/output isolationComputer peripheral interfaceDigital Fieldbus isolation: CC-link, DeviceNet, Profibus, SDSHigh-speed A/D and D/A conversionAC plasma display panel level shiftingMultiplexed data transmissionDigital control power supplyGround loop eliminationWhere to Use 6N137 Optocoupler?The 6N137 is a High-Speed Optocoupler or Optoisolator. As we know the term Optocoupler/optoisolator means we use light to indirectly couple (isolate) two sets of circuits. The speciality of 6N137 is that it has a high speed LED and hence can switch at 10Mbit/sec the output is NAND gate logic with an open drain transistor as one input and Enable pin as another input.The typical operating voltage of 6N137 is only 5V hence it cannot switch high loads and can also sink a maximum of only  7mA on its output side. So if you looking for some high voltage AC/DC switching try the 6N137. Apart from that the IC also has an Enable pin which comes in handy while designing a strobe circuit for your camera flash.So if you are looking for a high-speed optocoupler for some digital applications like data conversion or noise elimination then this IC might be of interest to you.How to Use 6N137 Optocoupler?Even though 6N137 is capable of working with both AC and DC it is commonly used with Digital circuits and works with 5V as supply voltage. A typical application circuit for 6N137 from the datasheet is shown below.The Capacitor 0.1uF is a bypass capacitor across the supply rail. The input signal should have an impedance of minimum 50 ohms with rising time and falls of 5nS of greater for the IC to respond. The input signal can be probed (if required) on pin 3 and the pulldown resistor Rm is optional and can be used only if you are connecting the signal to scope.As told earlier the output (pin 6) is an open-drain transistor and hence it can either sink current or remain floating. So to avoid floating we should use a pull-up resistor RL, the value of RL can be between 330 ohms to 4K depending upon the load connected.The pin 7 is the Enable pin, this pin has an in-built pull up resistor hence by default the IC is enabled when powered. When connected to ground it will disable the output. The pin can be put into use to create strobe circuits etc.. The below truth table will help you understand the working of Enable pin.Since the output is of open-drain type, note that when the input is high the output will be low and vice versa. Since the IC is commonly used for fast switching another thing to consider is the propagation delay. When the input is logic on the output turn off only after 48ns (TELH) and when the input is logic off the output turns on only after 50ns (TEHL). The same can be understood with the below switching diagram.6N137 EquivalentsHCPL4503MAlternatives Opto-couplers ：MOC3021 (Zero-crossing), MCT2E (non-Zero transistor), MOC3041 (Non-Zero Cross TRIAC), FOD3180 (High-Speed MOSFET),  PC817, 4N256N137 Package Outline6N137 Popularity by Region6N137 Market Price Analysis6N137 ManufacturerVishay Intertechnology was founded in 1962 by Dr. Felix Zandman. It began operations with one technology that had two product lines: foil resistors and foil resistance strain gages. In 1985, having grown from a start-up into the world’s leading manufacturer of these original products, the Company began an ongoing series of strategic acquisitions to become a broadline manufacturer of electronic components. Today, Vishay Intertechnology is one of the world’s largest manufacturers of discrete semiconductors and passive electronic components. These components are used in virtually all types of electronic devices and equipment, in the industrial, computing, automotive, consumer, telecommunications, military, aerospace, power supplies, and medical markets.Component Datasheet6N137 Datasheet

IntroductionThe LM2576 series of monolithic integrated circuits provide all the active functions for a step-down (buck) switching regulator. LM2576 series are capable of driving a 3A load with excellent line and load regulation. The regulators are simple to use because they require a minimum number of external components and include internal frequency compensation and a fixed-frequency oscillator.CatalogIntroductionCatalogI Voltage Stabilizing CircuitII Buck CircuitIII Current Boost CircuitFAQOrdering & QuantityI Voltage Stabilizing CircuitThe basic voltage stabilizing circuit composed of LM2576  only needs four peripheral devices, and its circuit is shown in Figure 1. The selection of inductance L1 depends on the output voltage, maximum input voltage, and maximum load current of LM2576,  First, the electric voltage microsecond constant (E·T) can be calculated according to the following formula:E·T=(Vin - Vout)&TImes;Vout/ Vin&TImes;1000/f (1)Vin is the maximum input voltage of LM2576; Vout is the output voltage of LM2576; f is the operating oscillation frequency value of LM2576  (52khz).Figure 1. Voltage Stabilizing CircuitGenerally, the input capacitance  Cin in the circuit should be greater than or equal to 100 μF. when installing, it is required to be close to the input pin of lm2576 as far as possible, and its withstand voltage value should match the maximum input voltage value.The value of the output capacitor Cout (unit μF) should be calculated according to the following formula:C≥13300 Vin/ Vout&TImes;L (2)Vin is the maximum input voltage of LM2576; Vout is the output voltage of LM2576; L (unit μH) is the value of inductance L1. The withstand voltage value of capacitor C should be 1.5 ~ 2 times of rated output voltage. For 5V voltage output, it is recommended to use a capacitor with a voltage withstand value of 16V.The rated current of diode D1 should be 1.2 times the maximum load current. Considering the state of the short circuit and load, the rated current of the diode should be greater than the maximum current limit of LM2576. The reverse voltage  of the diode should be greater than 1.25 times the maximum input voltage,  The selection of Vin should consider the input voltage  value of LM2576  corresponding to the lowest AC voltage drop (Vac-min) and the minimum input allowable voltage value Vmin of  LM2576,  Therefore, Vin can be calculated according to the following formula:Vin≥(220Vmin/Vac-min)If the minimum allowable AC voltage drop is 30% (Vac-min=154V) and the voltage output of the LM2576  is 5V (Vmin=8V), when Vac=220V, the input DC voltage of the LM2576  should be greater than 11.5V, usually 12V.II Buck CircuitThe buck circuit composed of LM2576 is shown in Figure 2. The output voltage is divided and sampled by R1 and R2, and then sent to the positive input end of the subtractor. The negative terminal is connected to VSET. The VSET signal is the voltage signal given by the microcontroller. The error signal is obtained by the output sample voltage subtracting the D/A conversion voltage. Then add the error signal to the reference voltage (VREF) 1.23V, and send this result to the feedback terminal of LM2576.Figure 2. Buck CircuitCompared with traditional direct feedback, the feedback loop in this design is more complicated. This design is mainly due to the following considerations: First, it is easy to control single-chip microcomputer. As long as the output voltage of D/A conversion is changed, the feedback loop works, and the output sampling voltage is automatically approached to the D/A conversion voltage.  Then the voltage adjustment process is complete. Second, it can meet the design requirements of zero voltage output. If simply use the feedback pin of the LM2576.  The minimum output of the reference circuit given in the manual can only reach 1.25V, so you need to "shift" the feedback voltage to a VREF reference voltage level.The voltage divided by the feedback resistor is also sent to the DAC  of the microcontroller.III Current Boost Circuit(a) Fixed output type; (b) adjustable output typeFigure 3. Current Boost CircuitFAQWhere is LM2576 used?LM2576 is usually used as a voltage stabilizing device when the input and output voltage difference is large and the output current is also large. Because it is a switching regulator, it has a higher conversion efficiency and low heat generation than a linear regulator.What’s the difference between LM2576T-ADJ and LM2576S-ADJ?LM2576T-ADJ is the package of TO-220, LM2576S-ADJ is the package of TO-263-5, there is no difference in their functions.What is the difference between LM2940 and LM2576? Which circuit are they applicable to?LM2940 is a low-dropout linear stabilized integrated circuit. The linear stabilized power supply is characterized by a relatively simple circuit, high precision, and small ripple coefficient. It is suitable for precision power supplies with high voltage requirements. The disadvantage is that the efficiency is very low and the output The current is relatively small (relative to the switching power supply)LM2576 is a switching power supply integrated circuit. Switching power supply, the circuit is more complicated, but the output current is large, the efficiency is high, the disadvantage is that the accuracy is lower and the ripple coefficient is larger.Why do switching power supply chips LM2576 and LM2596 have diodes, inductors and capacitors behind the output pins?The function of the diode and the inductance is that the output current can be continuous when the LM25XX is in the off state, and the function of the capacitor is to prevent the output voltage from sudden changes when the LM25XX is turned on and off. In fact, it is filtering.Why the higher the switching frequency of LM2576 and LM2596, the smaller the output inductance and capacitance value?Quite simply, the capacitive reactance of a capacitor decreases as the frequency increases, and the inductance of an inductor increases as the frequency increases. That is to say, the effect of using an inductance of 33uH in the case of 150Khz is basically the same as the effect of using an inductance of 100uH in the case of 52khz, and the principle of capacitance is the same. LM2596 is an upgraded version of LM2576. But LM2576 also has the advantage of less switching loss and less interference.

1N5408 is a diode of 1N540x series. It is a general purpose diode with many good features which makes it ideal to use in wide variety of general purpose applications. In the blog today,  we'll present you the comprehensive introduction to 1N5408 rectifier diode from pinout, features, to applications, where and how to use this diode, etc. Thank you for reading and hope this blog helps!Catalog1N5408 Description1N5408 Pinout1N5408 Features1N5408 CAD Models1N5408 Replacement and EquivalentWhere to Use 1N5408 diodeHow to Safely Long Run in a Circuit1N5408 Applications1N5408 Package1N5408 ManufacturerComponent DatasheetFAQ1N5408 Description1N5408 is a 1N540x series diode. It is a general purpose diode with many good features, making it ideal for use in a wide range of general purpose applications. For example, it is capable of handling up to 3A or 3000mA of current across it. It is manufactured in the DO201 package, which is a slightly larger DO-41 package, but can be used to replace many DO-41 diodes if a slightly larger space is available. It's also an ideal diode if you're looking for a bit more ampere handling capability compared to DO-41 diodes, such as 1N4007, 1N4148, etc. In most applications, you can replace these diodes with 1N5408 in order to get more forward current.1N5408 Pinout1N54081N5408 Pinout  Pin NameDescriptionAnodeCurrent always Enters through AnodeCathodeCurrent always Exits through Cathode1N5408 FeaturesHigh Current to Small SizeHigh Surge Current CapabilityLow Forward Voltage DropVoid-Free Economical Plastic PackageAvailable in Volume QuantitiesPlastic Meets UL 94V-0 for Flammability1N5408 CAD ModelsPart SymbolFootprint3D Model1N5408 Replacement and Equivalent1N5408 can easily be replaced by other diodes of its series, such as 1N5400, 1N5401, 1N5402, 1N5404, 1N5406 and 1N5407. The only differences between these diodes are the "Peak repetitive reverse voltage" and "Non repetitive reverse voltage’’, but as far as you use them in 12V to 24V circuits, there will be no problem. But if you use them in circuits above 12V to 24V, then you must check their "Peak repetitive and non-repetitive reverse voltages" and select a higher "Peak repetitive reverse voltage" than your operating voltage. Other possible equivalents include P300M, CR3-100, CR3-120, G3M, FR307, FR607, HER508 and V3510.Where to Use 1N5408 diodeAs mentioned above, 1N5408 can be used in many applications, it is mainly build to perform rectification in battery chargers, power supplies, voltage boosters, etc. But other than that it can be used in any general purpose applications that can block current in the desired direction in a circuit, block voltage spikes, etc.How to Safely Long Run in a CircuitIn order to achieve long-term performance in your project, circuit or device, it is suggested that you do not use this diode in circuits operating above 1000V, so that better performance is always kept below the maximum specification/characteristic values. Do not operate or drive more than 3A across this diode and always store and operate the device at temperatures above-65 centigrade and below +175 centigrade.1N5408 ApplicationsPower SuppliesBattery ChargersVoltage Doublers CircuitsAdaptersRectification CircuitsComponents Protection PurposesBlocking voltage and current in any desired direction1N5408 Package1N5408 ManufacturerON Semiconductor is driving energy efficient innovations, empowering customers to reduce global energy use. The company offers a comprehensive portfolio of energy efficient power and signal management, logic, discrete and custom solutions to help design engineers solve their unique design challenges in automotive, communications, computing, consumer, industrial, LED lighting, medical, military/aerospace and power supply applications.Component Datasheet1N5408 Diode DatasheetFAQWhat is 1N5408?The 1N5408 from Diode Inc is an axial leaded general purpose rectifier in DO-201AD package. The device features diffused junction, high current capability and low forward voltage and low reverse leakage current. Maximum repetitive reverse voltage Vrrm of 1kV. Non repetitive forward surge current IFSM of 200A. What is 1N5402 diode?The 1N5402 is a power diode because of its high forward current and reverse voltage with a power dissipation of 6.25W. For 1N5402 Diode, the maximum current carrying capacity is 3A it withstand peaks up to 200A. What is the maximum blocking voltage value for diode 1N5408?1N5408 is a high-power rectifier diode. Its maximum rectification current is 3A, and it supports a maximum reverse voltage of 1000V. When working at 1000V, the maximum reverse leakage current is 5μA (under standard temperature).

TL084 is a high-speed operational amplifier integrated circuit consisting of a high voltage JFET and bipolar transistor. An interesting project, using TL084 to build a 100w+100w stereo amplifier with step by step explanation, thumps up.CatalogTL084 DescriptionTL084 PinoutTL084 FeaturesTL084 EquivalentTL084 ParameterTL084 vs TL074Where to use TL084 op ampHow to use TL084 op ampTL084 ApplicationTL084 PackageComponent DatasheetTL084 DescriptionTL084 is a high-speed operational amplifier integrated circuit that is made up of a high voltage JFET and a bipolar transistor. It features low input bias currents, trimmed input offset voltage, and high slew rates.  It is also pin-compatible with the LM741 IC and is used in electronics and computers, among other things. Furthermore, its operation range is compatible with both common-mode and differential voltage range applications. When using TL084, ensure that the unused op-amp in this Quad package is terminated. Because if they are not terminated, they may develop some stay capacitance, which can cause noise and thus affect the overall performance of this device. Furthermore, unused op-amps consume more power, lowering device efficiency.TL084 PinoutTL084 Op AmpTL084 Pinout Pin NumberDetails1  output pin of 1st OP-AMP2  inverting input voltage to 1st OP-AMP3  non-inverting input voltage to 1st OP-AMP4 (Vcc+) connect the positive supply voltage5  non-inverting input voltage to 2nd OP-AMP6 an inverting input voltage to 2nd OP-AMP7  output of 2nd OP-AMP8  output of 3rd OP-AMP9  an inverting input voltage to 3rd OP-AMP10 non-inverting input voltage to 3rd OP-AMP11 (Vcc-)connecting negative supply voltage12  non-inverting input voltage to 4th OP-AMP13  an inverting input voltage to 4th OP-AMP14 output of 4th OP-AMPTL084 FeaturesWide common-mode Rejection ratio of 70dB to 86dB and wide voltage supply rangeA low input bias currentless Power RequirementInternal frequency compensationSupply current is 1.4mA which is very lowLow offset currentNo requirement of a latchHigh input impedance JFET input stageshort-circuit protection for outputa large gain bandwidth of 3MHzhigh input impedanceSlew rate is high typically 16 V/µsOperating temperature range is from –55 °C to +125 °CTL084 EquivalentTL074, LF353N, TL072TL084 ParameterManufacturer:Texas InstrumentsProduct Category:Operational Amplifiers - Op AmpsRoHS:DetailsSeries:TL084Amplifier Type:General Purpose AmplifierOperating Supply Current:1.4 mAMinimum Operating Temperature:- 40 CMaximum Operating Temperature:+ 125 CMounting Style:SMD/SMTPackage / Case:PDIP-14Packaging:TubeHeight:4.57 mmLength:19.3 mmWidth:6.35 mmBrand:Texas InstrumentsOperating Supply Voltage:7 V to 36 V, +/- 3.5 V to +/- 18 VProduct Type:Op Amps - Operational AmplifiersFactory Pack Quantity:25Subcategory:Amplifier ICsNumber of Channels:4 ChannelGBP - Gain Bandwidth Product:3 MHzCMRR - Common Mode Rejection Ratio:70 dB to 86 dBIb - Input Bias Current:200 pAVos - Input Offset Voltage:6 mVProduct:Operational AmplifiersSupply Type:Single, DualDual Supply Voltage:+/- 5 V, +/- 9 V, +/- 12 V, +/- 15 VMaximum Dual Supply Voltage:+/- 18 VMinimum Dual Supply Voltage:+/- 3.5 VUnit Weight:0.032734 ozSR - Slew Rate:13 V/usShutdown:No Shutdownen - Input Voltage Noise Density:18 nV/sqrt HzVcm - Common Mode Voltage:Negative Rail + 4 V to Positive Rail - 4 VSupply Voltage - Max:36 VSupply Voltage - Min:7 VVoltage Gain dB:106.02 dBTechnology:BiFETIn - Input Noise Current Density:0.01 pA/sqrt HzInput Type:Rail-to-RailTL084 vs TL074TL084TL074 The Op-Amp is very similar to TL074 but has high noise immunity and better offset characteristics. The '74 has lower noise figure, so is better for AC signals. The '84 has lower offset, so is better for DC signals. The TL084 has better DC performance (low offset) and the TL074 has better noise/distortion performance. You can use TL074s on the audio paths, TL084s on the control paths.Where to use TL084 op ampThe TL084 is suitable for all applications that require a high slew rate, low input bias current and offset voltage, and a wide bandwidth.  It is used in voltage followers, ac to dc conversions, sample and hold circuits, and high-speed integrators because it is an op-amp IC. It is used to carry out mathematical calculations. The TL084 Op-Amp is distinguished by the incorporation of high-voltage JFET and bipolar transistors, which allows the transistor to have a very high input impedance and a low bias current. This Op-Amp also has low noise and harmonic distortion, making it an excellent choice for audio pre-amplifiers. So, if you're looking for an Op-Amp IC with a Quad package that's JFET driven, this IC might be a good fit.How to use TL084 op ampThe TL084 Op amp is very similar to the LM324 Op-Amp in that they both contain four Op-Amps and have the same pinouts.  The TL084 is not intended for common 5V operation because it requires a minimum of 7V to operate. So, unlike the LM324 or other op-amps, if you use the Op-Amp in single supply mode, make sure you provide at least 7V for the Op-Amp to function normally. If you are interested in learning about a few basic application circuits of this IC, you can read about how LM324 is used because both ICs share the same applications.TL084 ApplicationSample and Hold AmplifiersIt is used in active Filters for amplifying the output signalComparators, Multivibrators, Peak Detectors, square wave oscillators, and function generators also use this IC for designing their internal circuits.It can be used to perform all Standard Operational Amplifier Applications as it is pin to pin compatible with the LM741 IC design.Operational amplifiers are used in Notch filters for removing a single frequency or a small band of frequencies. Therefore, this IC can also be used for performing this function.TL084 PackageComponent DatasheetTL084 Op Amp Datasheet 

BC337 is NPN Amplifier Transistor.Primarily, the BC337 used for lower power audio applications. It belongs to the NPN family of transistors and has a maximum gain of 630. The continuous collector current of 800mA indicates that it can drive loads up to 800mA.This post will introduce you the basic information of BC337 Transistor. You will learn some common descriptions, including:BC337 Transistor PinoutBC337 Transistor FeaturesComplementary PNP TransistorsBC337 Transistor EquivalentSMD EquivalentBC337 Transistor DescriptionBC337 Transistor ApplicationBC337 Transistor PackageComponent DatasheetBC337 Transistor PinoutPin NumberPin NameDescription1CollectorCurrent flows in through collector, normally connected to load2BaseControls the biasing of transistor, Used to turn ON or OFF the transistor3EmitterCurrent Drains out through emitter, normally connected to groundBC337 Transistor FeaturesGeneral Purpose NPN Amplifier TransistorCurrent Gain (hFE), 100 to 630Continuous Collector current (IC) is 800mACollector-Emitter voltage (VCEO) is 45 VCollector-Base voltage (VCB0) is 50VEmitter Base Voltage (VBE0) is 5VTransition Frequency 100MHzAvailable in To-92 PackageNote: You can find complete technical details in the BC337 data sheet at the end of this page.Complementary PNP TransistorsBC327BC337 Transistor Equivalent2N222, 2N4404, 2N3904SMD Equivalent2SC3913, 2SC3912BC337 Transistor DescriptionBC337 NPN TransistorThe BC337 is an NPN transistor commonly used in low-power amplifier circuits. A maximum gain (hfe) of 630 can be provided by the Transistor. The BC337 has three part names, the BC337-16 gain value is 100 to 250, the BC337-25 is 160 to 400 and the BC337-40 is 250 to 630. Other parameters are similar for all three part numbers, apart from the gain value.The transistor also has a high collector current of up to 800mA and a decent collector emitter voltage of 45V and a base trigger voltage of only 5V. This makes the transistor suitable for general purpose switching circuits. Due to its low base trigger voltage, digital circuits such as microcontroller circuits can be easily controlled. So, if you're looking for an audio amplifier transistor, you might consider the BC337. Also, look at the more commonly used 2N2222 Transistor if you're looking for a BC337 replacement to switch loads.BC337 Transistor Application BC337 Application: Mini Powerful Audio Amplifier using BC337 and BC327Low power audio amplifiersSmall signal amplifiersAudio frequency DriverAmplifier Output StageGeneral purpose switchingBC337 Transistor PackageIf you are designing a PCD or Perf board with this component, the following image from the Datasheet will be useful to know its package type and dimensions.3-Lead, TO-92, JEDEC TO-92 Compliant Straight Lead Configuration, Bulk Type3-Lead, TO-92, Molded, 0.2 In Line Spacing Lead Form, Ammo, Tape and Reel TypeComponent DatasheetBC337 Datasheet

IntroductionLM3886 is a high-performance audio power amplifier. It exhibits extremely low THD+N values of 0.03% at the rated output into the rated load over the audio spectrum and provides excellent linearity with an IMD (SMPTE) typical rating of 0.004%. It is very suitable for enthusiasts who pursue both beautiful sound quality and strong volume. This article introduces several practical applications of LM3886 in home theater systems.This is a technical examination vedio of the LM3886 Amplifier. Catalog IntroductionCatalogI High Quality Dual-channel Power AmplifierII Powerful BTL Power AmplifierIII Subwoofer SpeakerIV FAQOrdering & QuantityI High Quality Dual Channel Power AmplifierLM3886 outputs nearly 70W power at rated voltage and the peak power is 150W. The dual-channel power amplifier adopts a simple and typical circuit, which can replace a variety of HI-FI power amplifiers,  and is suitable for the left and right main channel of a power amplifier in home cinema. The whole circuit is installed on the same PCB. Each of the two LM3886s is equipped with a special aluminum radiator (length 140, thickness 50, height 75 (mm)), which are fixed on both sides of the PCB to facilitate heat dissipation. The power transformer can choose double 24～28V, 3～5A.II Powerful BTL Power AmplifierA pure BTL bridge amplifier is composed of an operational amplifier NE5532, an LM3886 in-phase amplifier, and an LM3886 inverting amplifier, which can easily output more than 200W undistorted power. It can be used in dance halls, karaoke, theaters, and other occasions. This circuit can keep the sound quality natural and smooth when playing at a low volume. BTL Power amplifier circuit is shown in Figure 1. One circuit board for each channel, with independent rectification. The size of the two radiators is 140mm in length, 50mm in thickness, and 100mm in height.　　Figure 1. BTL Power Amplifier CircuitIII Subwoofer SpeakerFigure 2 is the circuit of a household subwoofer speaker.　　Figure 2. circuit of subwoofer speakerIn the picture, the Linkwitz active compensator accurately controls the center frequency f1 of the compensation peak and its Q value, so that the closed box (see Figure 3) with a natural corner frequency of about 50 Hz and the frequency response curve (see Figure 4) extends down flatly. The low end -3dB point reaches 25Hz.Figure 3. Closed box　　Figure 4. frequency response curveIn Figure 4, curve A is natural frequency response; B is compensation curve; and C is system frequency response. The turning frequency of the low-pass filter is continuously adjustable from 80Hz to 200Hz, so that the active subwoofer can match the reader's dual channel speaker with different frequency limits. The loudspeaker uses silver flute YD310-43. The basin diameter is 310mm. The magnet diameter is 158mm. The resonance frequency is 25Hz. Q=0.35. The continuous power is 50W, and the sensitivity is as high as 95dB. Compared with the Hivi S8 unit with a sensitivity of 88dB, the sensitivity difference between the two is 7dB. For the closed box, the output sound pressure of Yindi YD310-43 when it input 50W is equivalent to the output of Hivi S8 unit when it input ≥200W.  Yindi can also be replaced by the Blue Whale YD310-8XA. Instead of the bass reflex with poor transient performance and low sensitivity, it is better to use the simplest closed box. The box shall be solid and air tight, filled with glass fiber cotton or acrylic cotton for warmth absorption, and the small cavity at the bottom of the box shall be used to install the circuit part. For the sake of simple installation, all circuits are installed on the PCB. The PCB, radiator, switch and I/O connector are fixed on the metal panel, and then fixed on the speaker with 6 screws. Then, it can work after connecting to horn and transformer. Connect the subwoofer active speaker with the home stereo speaker to form a 3D playback system.IV FAQWhat type of amplifier is LM3886?High-performance audio power amplifier What is the THD+N value of LM3886?0.03% What type of systems is LM3886 used for?Home theater systems What is the peak power of the LM3886?150W How much power does the LM3886 output at rated voltage?70W How much undistorted power can a BTL bridge amplifier output?200W