8.192 V shunt reference — what it buys the ADC rail
That output voltage is a common full-scale reference for 8-bit to 10-bit ADCs and for setting the feedback divider in a 5 V or 12 V regulator loop — 8.192 V gives a clean 8 mV per LSB at 10 bits, which simplifies the scaling math in firmware.
±1% tolerance and 115 µA cathode current
Rated at ±1% initial tolerance, the LM4040D82IDBZR holds the output within 82 mV of 8.192 V at 25 °C. The cathode current floor is 115 µA — below that the shunt loses regulation, so the bias resistor must be sized to keep at least 115 µA through the device at minimum input voltage and maximum load current. Maximum output current is 15 mA, which covers driving the reference input of most SAR ADCs without an external buffer.
SOT-23-3 footprint and temperature range
Housed in a standard SOT-23-3 (TO-236 / SC-59 compatible) package, the LM4040D82IDBZR fits a three-pin footprint shared with many shunt references — the anode, cathode, and no-connect (NC) pins are consistent across the LM4040 family. The temperature coefficient is 150 ppm/°C, so the output drifts about 1.2 mV over the full range — acceptable for 8-bit accuracy but worth derating for a 12-bit system.