1.225 V shunt reference with ±0.1% initial accuracy
The Texas Instruments LM4041AIZ-1.2/NOPB is a precision shunt voltage reference that delivers a fixed 1.225 V output with a tight ±0.1% initial tolerance. It is part of the LM4041 family, designed for applications where a stable, low-drift reference voltage is needed — think ADC reference biasing, comparator thresholds, or power-supply monitoring in industrial and consumer gear. As a shunt reference, it behaves like a Zener diode: you set the bias current with a single series resistor from the supply rail. The device regulates by shunting current to ground, so the load sees a steady 1.225 V as long as the cathode current stays above 65 µA and below the 12 mA maximum.
Temperature drift and noise — the precision story
The temperature coefficient is rated at 100 ppm/°C, which means the output voltage shifts by about 122.5 µV for every 10 °C change. Wideband noise from 10 Hz to 10 kHz is specified at 20 µVrms. That is low enough to not limit a 12-bit ADC's SNR in most signal-chain designs, though a small bypass cap (0.1 µF) across the output helps knock down high-frequency pickup from the board.
Through-hole TO-92 — easy to breadboard, easy to replace
The LM4041AIZ-1.2/NOPB comes in a TO-92-3 through-hole package (TO-226AA). That is the classic three-lead transistor-style package — cathode, anode, and no-connect. It is a natural fit for prototyping on perfboard or stripboard, and for production runs where wave-solder is the assembly process. For automated pick-and-place, look for the SOT-23 surface-mount variant of the LM4041 family.
You can design it into a new BOM today and expect multi-year supply continuity.