ST ISA046V1 User Manual

2 A / 1.2 V high-efficiency synchronous buck converter

evaluation board based on the ST1S09 with inhibit

Features

■ Input voltage range: 2.7 V to 5.5 V

■ Output voltage: 1.2 V

■ Max I

■ High internal switching frequency: 1.5 MHz

■ Inhibit function

■ Short-circuit protection

■ ST1S09I in the DFN6 3x3 package

Description

out

: 2 A

STEVAL-ISA046V1

Data Brief

This evaluation board, based on the ST1S09I
family of synchronous step-down DC-DC
converters, is optimized for powering all low­voltage applications and, generally, replaces high
current linear solutions when power dissipation
may cause high heating of the application
environment. It provides up to 2 A over an input
voltage range of 2.7 V to 5.5 V.

A high 1.5 MHz switching frequency allows the
use of tiny surface-mount components and in
addition to the resistor divider to set the output
voltage value, an inductor and two capacitors are
required.

The ST1S09I features an inhibit function.

A low output ripple is guaranteed by the current
mode PWM topology and by the use of low ESR
surface-mount ceramic capacitors.

The device is thermally protected and current
limited to prevent damage due to accidental short­circuit.

The ST1S09 family is available in the DFN6 3x3
package.

STEVAL-ISA046V1

March 2008 Rev 1 1/4

For further information contact your local STMicroelectronics sales office.

www.st.com

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Circuit schematic STEVAL-ISA046V1

1 Circuit schematic

Figure 1. Schematic

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