Data Brief

For further information contact your local STMicroelectronics sales office.

September 2008

Rev 1

1/4

4

STEVAL-ISA055V2

0.7 A / 3.3 V synchronous buck converter

with enable function based on the ST1S12XX

Features

DC converter

over temperature range

Description

This demonstration board is based on the

ST1S12 family of synchronous step-down DC-DC

converters optimized for powering low-voltage

digital cores in HDD (hard disk drive) applications,

and is generally used to replace high-current

linear solutions when power dissipation may

cause high heating of the application

environment.

It provides up to 0.7 A over an input voltage range

of 2.5 V to 5.5 V. A high switching frequency of 1.7

MHz allows the use of tiny surface-mount

components. A resistor divider to set the output

voltage value, an inductor, and two capacitors are

required for the adjustable version, while only an

inductor and 2 capacitors are needed for the 1.2 V

and 1.8 V fixed version.

A low output ripple is guaranteed by the current

mode PWM topology and by the use of low ESR

surface-mount ceramic capacitors.

The ST1S12 device is thermal protected and

current limited to prevent damage due to

accidental short-circuit. This family of products is

available in the TSOT23-5L package.

STEVAL-ISA055V2

www.st.com