Issue 3 - April 2008

1

www.zetex.com

© Zetex Semiconductors plc 2008

ZR431L

Adjustable precision shunt regulator

Summary

Description

The ZR431L is a three terminal adjustable shunt regulator offering excellent

temperature stability and output current handling capability up to 25mA.

The output voltage may be set to any chosen voltage between 1.24 and

10 volts by selection of two external divider resistors.

The devices can be used as a replacement for zener diodes in many

applications requiring an improvement in zener performance.

The ZR431L is particularly used in the feedback control loop of switch mode

power supplies. In this application the device 1.24 volt reference enables

the generation of low voltage supplies, typically 3.3 volts or 3 volts.

Features

•

2.5% and 1% tolerance

•

Max. temperature coefficient 50 ppm/°C

•

Temperature compensated for operation over -40 to 85°C

•

100mA to 25mA current sink capability

•

Surface mount SOT23 package

Applications

•

Switch mode power supplies

•

Shunt regulator

•

Series regulator

•

Voltage monitor

•

Over voltage / under voltage protection

Ordering information

Device

Pack

Part mark

Status

Quantity

per reel

Reel size

(inches)

TOL %

ZR431LF01TA

SOT23

43M

Active

3000

7

1

ZR431LF02TA

SOT23

43L

Active

3000

7

2.5

ZR431LC01STOB

TO92

ZR431L01

Obsolete

1500

1

ZR431LC02STOB

TO92

ZR431L02

Obsolete

1500

2.5

ZR431LC01L

TO92

ZR431L01

Obsolete

Loose

1

ZR431LC02L

TO92

ZR431L02

Obsolete

Loose

2.5