ST ISA084V1 User Manual

STEVAL-ISA084V1

STEVAL-ISA084V1

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

demonstration board with enable on/off based on the ST1S40

Features

■ V

: 4 V to 18 V

in

■ V

■ Maximum output current: 4 A

■ Switching frequency: 800 kHz

■ Short-circuit: protected

■ RoHS compliant

Description

The STEVAL-ISA084V1, based on the ST1S40, is
an internally compensated 800 kHz fixed­frequency PWM synchronous step-down
converter demonstration board.

The ST1S40 operates from 4.0 V to 18 V input,
while it regulates an output voltage as low as 0.8
V and up to V

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

out

: 3.3 V

(100% duty-cycle).

IN

Data brief

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

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

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

November 2011 Doc ID 022542 Rev 1 1/4

For further information contact your local STMicroelectronics sales office.

www.st.com

4

Circuit schematic STEVAL-ISA084V1

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1 Circuit schematic

Figure 1. Circuit schematic

2/4 Doc ID 022542 Rev 1