Patent attributes
A controller used in a resonant converter having a switching circuit and a resonant tank. The switching circuit has a high side switch and a low side switch. The controller has a feedback processing circuit for providing a reference signal based on a feedback signal. The reference signal changes at a first slope based on the feedback signal when the feedback signal is higher than a first voltage threshold, and the reference signal changes at a second slope based on the feedback signal when the feedback signal is lower than the first voltage threshold. The turning off of the high side switch is controlled by a high side off signal, which is generated based on the reference signal and a voltage sampling signal indicative a voltage across a resonant capacitor of the resonant tank.