STEVAL-ISA084V1 STMicroelectronics

STEVAL-ISA084V1 4 A peak, 800 kHz fixed-frequency PWM synchronous step-down demonstration board with enable on/off based on the ST1S40 Data brief Features V : 4 V to 18 V in V : 3.3 V out 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 fixed- frequency PWM synchronous step-down STEVAL-ISA084V1 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 (100% duty-cycle). IN The ST1S40 integrates 95 m high side switch and 69 m 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. 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 1 Circuit schematic Figure 1. Circuit schematic , ( 6). 6 / 6 54 6 7 6).3 6). IN A 34 3 %. 0 n OUT N SW I . 0 . & & 2/4 Doc ID 022542 Rev 1 2 & 2 37