STSR2

STSR2 Smart Driver IC provides two complementary high current outputs to drive Power Mosfets. The IC is dedicated to properly drive secondary Synchronous Rectifiers in medium power, low output voltage, high efficiency Forward Converters. From a synchronizing clock input, STSR2 generates two driving signals with the self-setting of dead time between complementary pulses. The IC operation prevents secondary side shoot-through conditions providing proper timing at the outputs turn-off transition. This smart function operates through a fast cycle-after-cycle control logic mechanism based on an internal high frequency oscillator, synchronized by the clock signal. A fixed anticipation in turning-off the OUTGATE1 with respect to the clock signal transition is provided,while the anticipation in turning off the OUTGATE2 can be set through external components. The adopted transitions revelation mechanism makes circuit operation independent by the forward magnetic reset technique used, avoiding most of the common problems inherent in self-driven synchronous rectifiers. A special Inhibit function allows the shut-off of OUTGATE2. This feature makes discontinuous conduction mode possible and prevents the freewheeling mosfet from sinking current from the output.

STSR2 automatically turns off the outputs when duty-cycle is lower than 13%, while STSR2M works even at very low duty-cycle values.