Method of operating a resonant push-pull converter in an above resonant frequency mode

Abstract

A method for operating a push-pull converter in an above resonant frequency operating mode, where the above resonant frequency operating mode produces a switching frequency that is higher than the natural operating resonant frequency of the converter circuit. As a result, the resonant period is longer than the turn-on period of each of the switches in the primary circuit. The push-pull converter has two power switches operating in alternating sequence. The push pull converter also includes a transformer with a primary winding coupled to the power switches and a secondary winding coupled to a secondary circuit, and an output capacitor. The method also includes generating an operating resonant frequency from a leakage inductance of the transformer in series with a an input capacitance; and generating a switching frequency for the power switches that is higher than the operating resonant frequency.

Dependencies are inferred from the claim text.