The LM4051BEM3-1.2 is a precision shunt voltage reference from Texas Instruments delivering a fixed 1.225 V output with ±0.2% initial tolerance. As a shunt (two-terminal) reference, it behaves like a Zener diode — a series resistor sets the bias current from the supply, and the reference regulates by shunting current to ground. The 12 mA maximum cathode current defines the load-driving ceiling and the minimum resistor value needed to keep the device in regulation across the supply range.
Temperature drift and noise — precision-grade stability
A temperature coefficient of 50 ppm/°C means the output voltage shifts by 61 µV per degree Celsius — tight enough for 12-bit ADC references in industrial control loops. The 20 µVrms noise (10 Hz to 10 kHz) is low enough that external filtering is optional for most 10- to 12-bit systems.
NRND status — plan the BOM transition
It remains available for existing production runs and repairs, but new designs should evaluate a pin-compatible successor before committing the BOM.