LM431SACMLX

Voltage Reference Overview

The LM431SACMLX is a programmable shunt regulator manufactured by ON Semiconductor, formerly Fairchild Semiconductor. It operates as a three-terminal adjustable voltage reference with an output range from approximately 2.5V to 36V. Key electrical parameters include a maximum input voltage of 37V and a maximum shunt current of 100mA. The device features an initial accuracy of 2% and a temperature coefficient of 50 PPM/°C. It functions within a temperature range of -25°C to +85°C and is housed in an SOT-89-3 surface-mount package.

Voltage Reference Feature Summary

• Programmable output voltage capability using two external resistors
• Low dynamic output impedance for stable regulation
• Active output circuit providing sharp turn-on characteristics

Voltage Reference Applications

• Replacement for Zener diodes in precision voltage reference circuits
• Adjustable power supply feedback loops
• Battery-operated equipment requiring stable reference voltages

Voltage Reference Procurement Notes

Verify the manufacturer designation, as ON Semiconductor acquired Fairchild's semiconductor business. Confirm the specific suffix 'LX' indicates tape and reel packaging if required for automated assembly. Ensure the component meets RoHS compliance standards relevant to your region. Cross-reference datasheets between ON Semi and legacy Fairchild documents to confirm pinout consistency for SOT-89-3 packages.

Voltage Reference Selection Notes

Select this component when a low-cost, high-accuracy shunt regulator is needed for voltage referencing or simple regulation tasks. The SOT-89-3 package suits applications with moderate space constraints compared to through-hole options. Consider the 50 PPM/°C temperature coefficient for thermal stability requirements. Evaluate the 100mA sink current limit against the maximum load current in the design.

Voltage Reference Part Context

The LM431 series is a widely used family of programmable shunt regulators. The LM431SACMLX represents the surface-mount variant in the SOT-89-3 package. It serves as a direct functional equivalent to the traditional TO-92 packaged LM431, offering similar electrical performance in a compact form factor suitable for modern PCB layouts.

Voltage Reference Replacement Considerations

Direct substitutes include LM431SACMFX (SOT-23F-3 package) and LM431SAI (TO-92 package). Verify pinout compatibility before substitution, as package differences may require layout adjustments.