5 V shunt reference — what it does in the circuit
The LM4040C50ILPR is a precision 5 V shunt voltage reference from Texas Instruments' LM4040 family. It provides a fixed 5 V output with ±0.5% initial tolerance, suitable for biasing ADCs, DACs, or setting a stable reference rail in mixed-signal and power-management circuits.
Noise, drift, and cathode current — the parametric floor
Minimum cathode current is 95 µA, and the shunt can sink up to 15 mA. The designer sizes the series resistor so the cathode current stays above 95 µA at the minimum supply voltage and below 15 mA at the maximum supply — standard shunt reference biasing.
Through-hole TO-92-3 package — mounting and footprint
The part comes in a TO-226-3 / TO-92-3 package with formed leads, intended for through-hole PCB mounting.