LM431SCCMFX

Voltage Reference Overview

The LM431SCCMFX is a three-terminal adjustable shunt regulator manufactured by onsemi in the SOT-23FL package. It provides programmable output voltage from approximately 2.5 V to 36 V using two external resistors. The device features a 0.5% initial accuracy reference voltage and operates within a temperature range of -25 °C to +85 °C. Key electrical specifications include a maximum cathode voltage of 37 V, a continuous cathode current range of 1 to 100 mA, and a typical dynamic output impedance of 0.2 Ω. The part is RoHS compliant and Pb-free.

Voltage Reference Feature Summary

• Programmable output voltage adjustable between 2.5 V and 36 V via external resistor divider
• Temperature compensated for stable operation across the full rated operating temperature range
• Active output circuitry delivers sharp turn-on characteristics suitable as a Zener diode replacement
• Low dynamic output impedance ensures precise regulation under varying load conditions

Voltage Reference Applications

• Shunt regulator circuits requiring precise voltage reference
• Output control stages for three-terminal fixed regulators
• High current shunt regulator configurations
• Current limit or constant-current source designs
• Constant-current sink applications

Voltage Reference Procurement Notes

Verify component authenticity through authorized onsemi distribution channels. Confirm package marking matches the specified SOT-23FL identifier. Ensure storage conditions remain within the stated limits to prevent moisture damage. Check for RoHS compliance documentation prior to assembly. Validate that the specific suffix corresponds to the required tolerance and temperature grade for the target design.

Voltage Reference Selection Notes

Select this variant when a 0.5% reference accuracy is required alongside surface-mount integration. Compare against LM431SA variants if lower cost or different tolerance levels suffice. Consider thermal resistance values for PCB layout planning. Verify that the operating temperature range meets environmental constraints. Evaluate pinout compatibility with existing footprint designs before finalizing the bill of materials.

Voltage Reference Part Context

This component belongs to the LM431 family of programmable shunt regulators. It shares functional similarities with LM431SA and LM431SB series devices but differs in output voltage tolerance and packaging. The SC designation indicates the specific accuracy class, while the CMFX suffix defines the SOT-23FL surface-mount package configuration. This family serves as a direct replacement for standard Zener diodes in precision regulation tasks.

Voltage Reference Replacement Considerations

LM431SACMFX and LM431SBCMFX are listed in the ordering information table. These parts share the same SOT-23FL package form factor. Differences exist in output voltage tolerance specifications. Verify electrical parameter alignment before substituting these components in existing designs.