LM431SAIMFX

Voltage Reference Overview

The LM431SAIMFX is a three-terminal adjustable shunt voltage reference manufactured by onsemi, formerly Fairchild Semiconductor. It operates within an input voltage range of 2.5V to 36V and provides an initial accuracy of ±2%. The device features a typical temperature coefficient of 50ppm/°C and supports a cathode current range from 1mA to 100mA. It is housed in a SOT-23F-3 surface-mount package and functions across a temperature range of -40°C to +85°C.

Voltage Reference Feature Summary

• Programmable output voltage capability using two external resistors
• Low dynamic output impedance for stable regulation
• Sharp turn-on characteristic replacing Zener diodes

Voltage Reference Applications

• Precision voltage references in power supply circuits
• Voltage monitoring and threshold detection systems
• Replacement for Zener diodes in regulator designs

Voltage Reference Procurement Notes

Verify the component status as End-of-Life (EOL) with onsemi before procurement planning. Confirm that the specific suffix 'MFX' corresponds to the required tape-and-reel packaging format. Ensure compatibility with existing PCB footprints for the SOT-23F-3 package during any design updates or sourcing alternatives.

Voltage Reference Selection Notes

Select this component when a low-cost, adjustable shunt regulator is required for space-constrained applications. The SOT-23F-3 package offers a compact solution compared to larger through-hole options. Consider the ±2% accuracy and 50ppm/°C temperature coefficient against application stability requirements.

Voltage Reference Part Context

This part belongs to the LM431 family of programmable shunt regulators. Originally developed by Fairchild Semiconductor, the product line is now managed by onsemi following corporate restructuring. The LM431 series is widely recognized as a standard industry replacement for fixed Zener diodes due to its adjustable nature and improved performance characteristics.

Voltage Reference Replacement Considerations

Public confirmed substitute part numbers include LM431SACMLX and LM431SACMFX from onsemi. These variants share similar electrical specifications but may differ in package type or manufacturing lot details.