Patent ID: 7598715

Claim:
A circuit for switching regulation, comprising: an error amplifier that is arranged to provide an error signal based, in part, on an output signal; a switch control circuit including a pulse modulation control circuit, wherein the switch control circuit that is arranged to provide a first switch control signal based on a pulse modulation control circuit input signal, wherein the first switch control signal controls opening and closing of a first switch circuit, and wherein the pulse modulation control circuit input signal is based, in part, on the error signal; a synchronous switch enable control circuit that is arranged to provide a synchronous switch enable signal such that, during a transition time interval, a modulation parameter of the synchronous switch enable signal is gradually increased or gradually decreased; a synchronous switch enable logic circuit that is arranged to provide a synchronous switch control signal based, in part, on the synchronous switch enable signal and the first switch control signal, wherein the synchronous switch control signal controls opening and closing of a synchronous switch circuit; and a level shift circuit that is arranged to provide the pulse modulation control circuit input signal during the transition time interval by level-shifting the error signal down by an amount that is based on a reverse current duration.