Diodes Incorporated

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The AP431S is a 3-terminal adjustable shunt regulator with guaranteed thermal stability over a full operation range. It features sharp turn-on characteristics, low temperature coefficient and low output impedance, which makes it ideal substitute for Zener diode in applications such as switching power supply, charger and other adjustable regulators.

The AP431S has the same electrical specifications as the industry standard 431 except that it features a low minimum cathode current for regulation. The typical value of 50μA makes the parts ideal for very low power dissipation applications.

The output voltage of AP431S can be set to any value between VREF (2.5V/2.495V) and the corresponding maximum cathode voltage (36V).

The AP431S is offered in two grade initial voltage tolerance at +25°C, 0.5% and 1%.

This IC is available in 3 packages: TO92 (ammo packing), SOT23 and SOT89.


  • Low Minimum Cathode Current for Regulation: 50μA (Typ.), 100μA (Max.)

  • Programmable Precise Output Voltage from 2.5V/2.495V to 36V

  • High Stability Under Capacitive Load

  • Low Deviation of Reference Voltage Over Full Temperature Range: 11mV Typical (-40°C to +125°C)

  • Sink Current Capacity from 100µA to 100mA

  • Low Dynamic Impedance: 0.1Ω (Typ.)

  • Wide Operating Temperature Range: -40°C to +125°C


  • Charger

  • Voltage Adapter

  • Switching Power Supply

  • Graphic Card

  • Precision Voltage Reference

Product Specifications

Product Parameters

Type Shunt regulator
Compliance (Only Automotive supports PPAP) Standard
AEC Qualified No
ReferenceVoltage (V) 2.5, 2.495 V
Tolerance (%) 0.5, 1 %
Maximum Input Voltage (V) 40 V
Sink Current (mA) 100 mA
Minimum Cathode Current for Regulation Typ (µA) 50 µA
Typical Temperature Coefficient (ppm/°C) 27 ppm/°C
Maximum Slope Resistance (Ω) 0.3 Ω
Operating Ambient Temperature Range (°C) -40 to 125 °C

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Product Change Notices (PCNs)

A PCN may only apply to specific orderable part numbers in this datasheet. Please refer to the corresponding PCN to see the exact orderable part number(s) affected.

PCN # Issue Date Implementation Date Subject
PCN-2512 2021-04-16 2021-07-16 Qualified Additional Assembly & Test (A/T) Site
PCN-2514 2021-03-09 2021-06-09 Additional Wafer Source JKFAB