KA431SMF2TF

Overview

The KA431SMF2TF is a programmable shunt regulator manufactured by onsemi, formerly Fairchild Semiconductor. It features an adjustable output voltage range from approximately 2.5V to 36V, set via two external resistors. The device offers an initial accuracy of 2% and a typical temperature coefficient of 50 PPM/°C. It operates within a temperature range of -25°C to +85°C and supports a maximum shunt current of 100mA with a maximum input voltage of 37V. The component is housed in a SOT-23F-3 surface-mount package.

Feature Summary

• Three-terminal adjustable regulator series with guaranteed thermal stability over the operating temperature range
• Active output circuitry provides sharp turn-on characteristics for effective zener diode replacement
• Low dynamic output impedance and low output noise voltage for stable reference performance

Applications

• Voltage reference applications requiring programmable output settings
• Power supply feedback loops utilizing shunt regulation
• Comparator circuits leveraging fast turn-on response

Procurement Notes

Verify end-of-life status carefully as this part is marked obsolete. Confirm availability through authorized distributors or secondary markets. Ensure the specific suffix matches design requirements. Check RoHS compliance details before integration. Validate that the SOT-23F-3 package fits the target PCB layout constraints.

Selection Notes

Select this component when a precise, adjustable voltage reference is needed in a compact surface-mount form factor. Consider the 2% initial accuracy and 50 PPM/C temperature coefficient for precision requirements. Evaluate the 100mA sink current capability against load demands. Ensure the 37V maximum input voltage exceeds the circuit's peak operating voltage.

Part Context

This device belongs to the KA431S series of high-current shunt regulators. It serves as a direct successor to legacy Fairchild Semiconductor parts following corporate integration. The KA431 family is widely recognized for replacing standard Zener diodes in precision analog and power management circuits due to its superior stability and adjustability.

Replacement Considerations

NCP432BISNT1G is listed as a potential manufacturer substitute.