ST ISA083V1 User Manual

STEVAL-ISA083V1

4 A peak 800 kHz fixed-frequency PWM synchronous step-down

demonstration board with enable on/off based on the ST1S40IPUR

Data brief

Features

■ Input voltage V

■ Output voltage V

■ Maximum output current: 4 A

■ Switching frequency: 800 kHz

■ Short-circuit protected

■ RoHS compliant

: 4 V to 18 V

in

: 3.3 V

out

Description

The STEVAL-ISA083V1, based on the
ST1S40IPUR, is an internally compensated 800
kHz fixed-frequency PWM synchronous step­down converter demonstration board.

The ST1S40 operates from 4.0 V to 18.0 V input,
while it regulates an output voltage as low as 0.8
V and up to V

The ST1S40 integrates a 95 mΩ high-side switch
and a 69 mΩ synchronous rectifier allowing very
high efficiency with very low output voltage.

The peak current mode control with internal
compensation delivers a very compact solution
with a minimum component count.

(100% duty cycle).

IN

STEVAL-ISA083V1

The ST1S40 is protected through cycle-by-cycle
current limiting in case of overload and is also
protected by a current foldback function with
frequency reduction in case of short-circuit.

The device is available with an enable on/off
function.

September 2011 Doc ID 022278 Rev 1 1/4

For further information contact your local STMicroelectronics sales office.

www.st.com

4

Schematic STEVAL-ISA083V1

1 Schematic

Figure 1. Circuit schematic

6). 6

#IN?A

 n &

#IN?SW

&

6).37

6).!

%.0'

0'.$!'.$

343

37

&"

,(

2

2

6/546

#OUT

&

2/4 Doc ID 022278 Rev 1