STMicroelectronics 4 A peak, 800 kHz fixed-frequency PWM synchronous step-down demonstration board with enable on/off based on the ST1S40 S STEVAL-ISA084V1 Fiche De Données

   

   

   

For further information contact your local STMicroelectronics sales office.

November 2011

Doc ID 022542 Rev 1

1/4

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

demonstration board with enable on/off based on the ST1S40

■

V

in

: 4 V to 18 V

■

V

out

: 3.3 V

■

Maximum output current: 4 A

■

Switching frequency: 800 kHz

■

Short-circuit: protected

■

RoHS compliant

The STEVAL-ISA084V1, based on the ST1S40, is 
an internally compensated 800 kHz fixed-
frequency 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

IN

 (100% duty-cycle).

The ST1S40 integrates 95 m

Ω high side switch 

and 69 m

Ω synchronous rectifier allowing very 

high efficiency with very low output voltages.

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.