STSR2 Datasheet | STMicroelectronics

FORWARD SYNCHRONOUS RECTIFIERS SMART DRIVER s s s s s s SUPPLY VOLTAGE RANGE: 4.5V TO 5.5V TYPICAL PEAK OUTPUT CURRENT: SOURCE -2A, SINK 3.5A OPERATING FREQUENCY: 20 TO 750 KHZ SMART TURN-OFF ANTICIPATION TIMING OPERATION INDEPENDENT FROM THE FORWARD MAGNETIC RESET TECHNIQUE POSSIBILITY TO OPERATE IN DISCONTINUOUS MODE SO-8 .. DESCRIPTION STSR2 Smart Driver IC provides two plementary 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 plementary 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 OUT GATE1 with respect to the clock signal transition is provided, SCHEMATIC DIAGRAM Vcc 2 while the anticipation in turning off the OUTGATE2 can be set through external ponents. The adopted transitions revelation mechanism makes circuit operation independent by the forward magnetic reset technique used, avoiding most of the mon 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. + BIAS UVLO 5.7V CK 4 PEAK DETECTOR ANTICIPATION SET 3 SETANT2 + + HIGH FREQUENCY OSCILLATOR 1 OUTGate1 DIGITAL CONTROL OUTPUT BUFFERS 7 OUTGate2 INHIBIT 5 + 25m V SGLGND PWRGND June...