Quasi-resonant converter

Switching converters are broadly classified into resonant and non-resonant types. Resonant converters control switching operation using a sinusoidal AC voltage or current. In contrast, non-resonant converters control switching operation through pulse width modulation. A quasi-resonant converter incorporates the advantages of both resonant and non-resonant converters to reduce switching losses, and controls switching operation using a quasi-sinusoidal wave that combines distorted and trapezoidal waveforms. Quasi-resonant converters offer high efficiency under relatively stable load conditions and are therefore used in applications such as auxiliary power supplies in power conversion systems.