IR1176

Preliminary Data Sheet PD60185-C IR1176 SYNCHRONOUS RECTIFIER DRIVER Features Provides constant and proper gate drive to power Product Summary Vdd IO+/- (peak) Fmax Max lead time 5Vdc 4A/4A 2MHz 500nsec MOSFETs regardless of transformer output Minimizes loss due to power MOSFET body drain diode conduction Stand alone operation - no ties to primary side Schmitt trigger input with double pulse suppression allows operation in noisy environments High peak current drive capability - 4A High speed operation - 2MHz Adaptable to multiple topologies Description The IR1176 is a high speed CMOS controller designed to drive N-channel power MOSFETs used as synchronous rectifiers in high current, high frequency forward converters with output voltages equal or below 5VDC. Schmitt trigger inputs with double pulse suppression allow the controller to operate in noisy environments. The circuit does not require any ties to the primary side and derives its operating power directly from the secondary. The circuit functions by anticipating transformer output transitions, then turns the power MOSFETs on or off before the transitions of the transformer to minimize body drain diode conduction and reduce associated losses. Turn on/off lead time can be adjusted to accommodate a variety of power MOSFET sizes and circuit conditions. The IR1176 also provides gate drive overlap/dead-time control via external components to further minimize diode conduction by nulling effects of secondary lo...