Patent ID: 8907638

Claim:
A power converter, comprising: an inductor with an inductance of L coupled between an input, which receives an input voltage V in , and a peaking node, wherein the total voltage at the peaking node is V pk ; a low-side switch coupled between the peaking node and a base voltage; a high-side switch coupled between the peaking node and an output, which produces an output voltage V o and an output current I o ; and a controller which cycles the low-side switch between on and off states with a cycle time T cycle , wherein during the on state, current can flow from the inductor through the low-side switch, and wherein during the off state, current can flow from the inductor through the high-side switch to the output; wherein during the off state, the controller waits to turn on the low-side switch until the inductor current I L decreases from a peak current I pk to zero and then goes negative, wherein the negative inductor current resonantly discharges power through the input, wherein at least some of the resonantly discharged power is recovered after the low-side switch is turned on; wherein the controller turns on the low-side switch before I L returns to zero and when V pk drops to zero; and wherein during the on state, the controller waits to turn off the low-side switch until the inductor current I L reaches I pk =2I o (V o /V in ).