{"product_id":"tl431-sot23-adjustable-precision-shunt-voltage-reference-ic-20pack","title":"TL431 SOT-23 Adjustable Precision Shunt Voltage Reference IC 2.5V–36V (20-Pack)","description":"\u003ch2\u003eTL431 SOT-23 Adjustable Precision Shunt Voltage Reference IC — 2.5V–36V (20-Pack)\u003c\/h2\u003e\u003cp\u003eThe \u003cstrong\u003eTL431\u003c\/strong\u003e is a three-terminal adjustable shunt voltage reference in a compact \u003cstrong\u003eSOT-23\u003c\/strong\u003e surface-mount package. With a reference voltage of \u003cstrong\u003e2.495V\u003c\/strong\u003e (adjustable up to 36V via external resistors), \u003cstrong\u003e0.5% initial accuracy\u003c\/strong\u003e, and operation from 1mA to 100mA, it is the most widely used precision reference IC in \u003cstrong\u003eSMPS optocoupler feedback loops\u003c\/strong\u003e, voltage monitors, and precision reference circuits.\u003c\/p\u003e\u003ch3\u003eKey Specifications\u003c\/h3\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003cth\u003eParameter\u003c\/th\u003e\n\u003cth\u003eValue\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePart Number\u003c\/td\u003e\n\u003ctd\u003eTL431 \/ TL431A\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003ePackage\u003c\/td\u003e\n\u003ctd\u003eSOT-23 (SMD)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eReference Voltage (VREF)\u003c\/td\u003e\n\u003ctd\u003e2.495V (internal, ±0.5% for TL431A)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eAdjustable Output Range\u003c\/td\u003e\n\u003ctd\u003e2.5V – 36V (via R1\/R2 divider)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eCathode Current Range\u003c\/td\u003e\n\u003ctd\u003e1mA – 100mA\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eTemperature Coefficient\u003c\/td\u003e\n\u003ctd\u003e~50ppm\/°C typical\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eDynamic Impedance\u003c\/td\u003e\n\u003ctd\u003e0.22Ω typical\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eOperating Temperature\u003c\/td\u003e\n\u003ctd\u003e0°C to +70°C (TL431) \/ −40°C to +85°C (TL431A)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003eQuantity\u003c\/td\u003e\n\u003ctd\u003e20 pieces\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch3\u003eOutput Voltage Setting Formula\u003c\/h3\u003e\u003cp\u003eVOUT = VREF × (1 + R1\/R2) = 2.495 × (1 + R1\/R2)\u003c\/p\u003e\u003ctable\u003e\n\u003ctr\u003e\n\u003cth\u003eTarget VOUT\u003c\/th\u003e\n\u003cth\u003eR1 (kohm)\u003c\/th\u003e\n\u003cth\u003eR2 (kohm)\u003c\/th\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e2.5V\u003c\/td\u003e\n\u003ctd\u003e0 (short)\u003c\/td\u003e\n\u003ctd\u003eAny\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e5.0V\u003c\/td\u003e\n\u003ctd\u003e10k\u003c\/td\u003e\n\u003ctd\u003e10k\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e12.0V\u003c\/td\u003e\n\u003ctd\u003e38k\u003c\/td\u003e\n\u003ctd\u003e10k\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e15.0V\u003c\/td\u003e\n\u003ctd\u003e50k\u003c\/td\u003e\n\u003ctd\u003e10k\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/table\u003e\u003ch3\u003eWhy Choose TL431?\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e0.5% Accuracy (TL431A)\u003c\/strong\u003e — Precise reference for SMPS feedback and ADC reference applications\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eAdjustable 2.5V–36V\u003c\/strong\u003e — Two resistors set any output voltage in range\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eLow Dynamic Impedance\u003c\/strong\u003e — 0.22Ω provides stable reference under varying load current\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSOT-23 Package\u003c\/strong\u003e — Minimal PCB footprint for compact SMPS and charger designs\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIndustry Standard\u003c\/strong\u003e — Used in virtually every SMPS feedback loop; extensive reference designs available\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eTypical Applications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003eSMPS optocoupler feedback loop (flyback, forward converter output regulation)\u003c\/li\u003e\n\u003cli\u003ePrecision voltage reference for ADC and DAC circuits\u003c\/li\u003e\n\u003cli\u003eOvervoltage protection threshold detector\u003c\/li\u003e\n\u003cli\u003eBattery voltage monitor and low-battery alarm\u003c\/li\u003e\n\u003cli\u003eLinear regulator replacement (shunt regulator)\u003c\/li\u003e\n\u003cli\u003eLED constant-current driver reference\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eSMPS Feedback Circuit\u003c\/h3\u003e\u003cp\u003eTL431 REF pin connects to R1\/R2 voltage divider from VOUT. Cathode connects to optocoupler LED anode via series resistor. Anode to GND. When VOUT rises above setpoint, TL431 conducts more current through optocoupler, reducing PWM duty cycle to regulate output.\u003c\/p\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eQ: What is the difference between TL431 and TL431A?\u003c\/strong\u003e\u003cbr\u003eA: TL431A has tighter initial accuracy (±0.5% vs ±2% for standard TL431) and lower temperature coefficient. Use TL431A for precision applications; standard TL431 for general SMPS feedback.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eQ: Can TL431 replace a zener diode?\u003c\/strong\u003e\u003cbr\u003eA: Yes — TL431 is a programmable zener with much tighter tolerance and lower dynamic impedance than standard zener diodes. It is the preferred choice for precision voltage clamping.\u003c\/p\u003e\u003ch3\u003ePackage Contents\u003c\/h3\u003e\u003cul\u003e\u003cli\u003e20× TL431 SOT-23 Adjustable Shunt Voltage Reference IC\u003c\/li\u003e\u003c\/ul\u003e","brand":"Keszoox","offers":[{"title":"Default Title","offer_id":46991508832491,"sku":"\u003cnone\u003e","price":4.88,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0677\/1005\/8731\/files\/tl431-sot23-adjustable-voltage-reference-ic-chip.webp?v=1761366497","url":"https:\/\/keszoox.com\/products\/tl431-sot23-adjustable-precision-shunt-voltage-reference-ic-20pack","provider":"Keszoox","version":"1.0","type":"link"}