data brief for further information contact your local stmicroelectronics sales office. november 2011 doc id 022542 rev 1 1/4 4 STEVAL-ISA084V1 4 a peak, 800 khz fixed-freque ncy pwm synchronous step-down demonstration board with enab le on/off based on the st1s40 features 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 description the STEVAL-ISA084V1, base d 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 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. STEVAL-ISA084V1 www.st.com
circuit schematic STEVAL-ISA084V1 2/4 doc id 022542 rev 1 1 circuit schematic figure 1. circuit schematic 6 ) . 3 7 3 7 & |