Patent ID: 8212493
Filing Date: 2012-07-03
Classification: H02M

Abstract:
1. A cascaded power converter, comprising: a first switched-power circuit having an input coupled to a power source and an output coupled to an intermediate node; and a second switched-power circuit having an input coupled to the intermediate node and an output providing an output of the cascaded power converter, wherein the second switched-power circuit includes a magnetic coupling element for coupling the input of the second switched-power circuit to the output of the first switched-power circuit and having a primary winding and an auxiliary winding, wherein the second switched-power supply includes a control circuit that causes the second switched-power circuit to operate in a low energy transfer operating mode when a voltage at the intermediate node is below a normal operating voltage or when the output of the cascaded power converter is effectively disabled by the control circuit stopping normal switching operation of the second switched-power circuit, wherein in the low energy transfer operating mode, energy sufficient to operate the control circuit from the auxiliary winding is transferred to the auxiliary winding.