FAN431ZXA

Overview

The FAN431ZXA is a programmable shunt regulator from the FAN431 series, manufactured by onsemi. It functions as a three-terminal adjustable voltage reference with an internal reference voltage of approximately 2.5V. The device allows output voltage setting between V_REF and 36V using two external resistors. Key electrical parameters include a typical dynamic output impedance of 0.2Ω, a sink current capability ranging from 1.0mA to 100mA, and a temperature coefficient of 50ppm/°C. It operates within a temperature range of -25°C to +85°C.

Feature Summary

• Programmable output voltage adjustable via external resistors
• Low dynamic output impedance for stable regulation
• Temperature compensated operation across full rated range
• Fast turn-on response suitable for Zener diode replacement

Applications

• Precision voltage references in power supplies
• Replacement for Zener diodes in regulation circuits
• Adjustable shunt regulators in industrial equipment

Procurement Notes

Verify the manufacturer designation carefully, as the component was originally produced by Fairchild Semiconductor before its acquisition by onsemi. Confirm that the specific suffix 'Z' corresponds to the required packaging type (such as TO-92 Ammo or Tape and Reel) as indicated in the official datasheet documentation. Ensure compatibility with the specified operating temperature range of -25°C to +85°C for your application environment.

Selection Notes

Select this component when a low-cost, adjustable shunt regulator is required to replace standard Zener diodes. It is suitable for applications demanding a sharp turn-on characteristic and low dynamic output impedance. Consider the thermal stability and temperature coefficient if the circuit operates under varying environmental conditions. Ensure the required output voltage falls within the 2.5V to 36V range supported by the external resistor network.

Part Context

The FAN431ZXA belongs to the FAN431/FAN431A/FAN431L family of programmable shunt regulators. This series provides a versatile solution for voltage reference and regulation tasks where fixed Zener diodes are insufficient. The devices are designed for surface mount and through-hole applications, offering thermal stability and precise control over output voltage settings through simple external resistor configurations.

Replacement Considerations

The datasheet explicitly identifies the device as an excellent replacement for Zener diodes in many applications due to its active output circuit and sharp turn-on characteristic. No other specific substitute part numbers are documented in the provided source material.