Switching regulator for power converter with dual mode feedback input and method thereof

摘要

A switching power supply (10) uses a switching regulator (18) that is capable of operating in a dual mode with either primary side regulation or secondary side regulation. The primary and secondary side regulation schemes generate opposite phase feedback signals. The switching regulator has first (56, 62) and second (70, 74) detectors on the feedback input which detect when the feedback signal is less than a first value and also detect when the feedback signal is greater than a second value. By monitoring either case, the switching regulator can enable and disable a gate drive signal in response to opposite phases of the feedback signal and thereby regulate the switching power supply.