3.0 V fixed shunt reference in a TO-92-3
The Texas Instruments LM4040CIZ-3.0/NOPB is a precision shunt voltage reference that delivers a fixed 3 V output with ±0.5% initial tolerance. Output noise is specified at 35 µVrms over a 10 Hz to 10 kHz bandwidth, and the temperature coefficient is 100 ppm/°C — both figures that matter when the reference sits ahead of a 12-bit or 14-bit converter in a temperature-varying environment.
If your pick-and-place line is SMT-only, the through-hole body will require a separate hand-solder or wave-solder step, adding process cost. Consider a pin-compatible SMT alternative in the LM4040 family if board-space and assembly flow allow.
Key parametric limits for BOM fit
The shunt reference can sink up to 15 mA of output current, with a minimum cathode current of 65 µA to maintain regulation. With a 100 ppm/°C drift and ±0.5% initial tolerance, the total error budget across temperature is roughly ±0.5% ± (100 ppm × ΔT). For a 3 V output, that is about ±15 mV at 25°C, plus another ±30 mV over a 60°C swing — enough to flag if your ADC reference input expects better than 1% total accuracy.