AS431

Document number: DS36599 Rev. 4 - 2

1 of 20

www.diodes.com

May 2018

© Diodes Incorporated

AS431

ADJUSTABLE PRECISION SHUNT REGULATORS

Description

The AS431 is a three-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 make it ideal substitute for Zener diode in

applications such as switching power supply, charger and other

adjustable regulators.

The output voltage of AS431 can be set to any value between VREF

(2.5V) and the corresponding maximum cathode voltage (36V).

The AS431 precision reference is offered in two voltage tolerance:

0.5% and 1.0%.

This IC is available in 4 packages: TO92 (Ammo Packing), SOT23,

SOT25 and SOT89.

Features



Programmable Precise Output Voltage from 2.5V to 36V



High Stability under Capacitive Load



Low Temperature Deviation: 4.5mV Typical



Low

Equivalent

Full-range

Temperature

Coefficient

with

20PPM/°C Typical



Sink Current Capacity from 1mA to 100mA



Low Output Noise



Wide Operating Range of -40 to +125°C



Lead-Free Packages: SOT23, SOT25, TO92 (Ammo Packing),

SOT89



Totally Lead-Free; RoHS Compliant (Notes 1 & 2)



Lead-

Free Packages, Available in “Green” Molding Compound:

SOT23, SOT25, TO92 (Ammo Packing), SOT89



Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)



Halogen and Antimony Free. “Green” Device (Note 3)

Applications



Charger



Voltage Adapter



Switching Power Supply



Graphic Card



Precision Voltage Reference

Pin Assignments

(Top View)

(Top View)

SOT23

SOT25

Note 4: * Pin 2 is attached to substrate and must be connected to ANODE or

open.

(Top View)

(Top View)

SOT89 (Option 1)

SOT89 (Option 2)

(Top View)

TO92 (Ammo Packing)

Notes:

1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS), 2011/65/EU (RoHS 2) & 2015/863/EU (RoHS 3) compliant.

2. See https://www.diodes.com/quality/lead-free/ for more inf

ormation about Diodes Incorporated’s definitions of Halogen- and Antimony-free, "Green" and

Lead-free.

3. Halogen- and Antimony-

free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and

<1000ppm antimony compounds.

ANODE

CATHODE

REF

3

2

1

1

2

3

REF

CATHODE

ANODE

1

2

3

REF

CATHODE

ANODE

REF

CATHODE

ANODE

1

2

3

4

5

NC

(Note 4)

*

REF

CATHODE

ANODE

1

2

3