LM431ACMX

Voltage Reference Overview

The LM431ACMX is a three-terminal adjustable precision shunt regulator manufactured by Fairchild Semiconductor. It provides a programmable output voltage ranging from approximately 2.5 volts to 36 volts, set via two external resistors. The device features a typical dynamic output impedance of 0.2 ohms and supports a sink current capability between 1.0 mA and 100 mA. It exhibits an equivalent full-range temperature coefficient of 50 ppm/°C and operates within a temperature range of -40°C to +85°C.

Voltage Reference Feature Summary

• Programmable output voltage adjustable between the internal reference level and 36 volts using external resistors
• Low dynamic output impedance ensuring stable regulation performance under varying load conditions
• Temperature compensated design maintaining stability across the full rated operating temperature range

Voltage Reference Applications

• Replacement for Zener diodes in voltage reference circuits
• Precision voltage regulation in power supply designs
• Adjustable shunt regulation in battery management systems

Voltage Reference Procurement Notes

Verify the specific suffix 'CMX' against the official Fairchild Semiconductor datasheet to confirm package type and tape-and-reel specifications. Ensure the component matches the required thermal stability and accuracy grades defined in the original documentation before procurement.

Voltage Reference Selection Notes

Select this component when a low-cost, adjustable shunt regulator with high precision is required. Consider the 50 ppm/°C temperature coefficient and 0.2-ohm dynamic impedance for applications demanding stable reference voltages over wide temperature variations.

Voltage Reference Part Context

The LM431 series represents a widely used family of three-terminal adjustable shunt regulators. The LM431ACMX variant specifically denotes the Fairchild Semiconductor manufacturing origin and packaging configuration. This part belongs to the broader category of precision voltage references utilized in analog circuit design.

Voltage Reference Replacement Considerations

Compatible substitutes include the LM431AIM3/NOPB from Texas Instruments and the NCP431AISNT1G from onsemi. Verify pinout compatibility and electrical parameter alignment with the original datasheet before substitution.