Method and apparatus for dynamic voltage transition control in semi-resonant and resonant converters

摘要

A voltage converter includes a power stage coupled to a power source, a passive circuit coupling the power stage to an output capacitor, a synchronous rectification (SR) switch operable to couple the passive circuit to ground when the SR switch is conducting, a linear controller and an adaptive voltage positioning (AVP) circuit. The linear controller is operable to control switching of the SR switch and switch devices included in the power stage, to regulate an output voltage of the voltage converter based on a reference voltage. The AVP circuit operable to generate an offset voltage applied to the reference voltage based on a first signal representing output current of the voltage converter, and to subtract a second signal from the first signal. The second signal approximates a surge current applied to the output capacitor via the passive circuit for charging the output capacitor during transitions in the reference voltage.