Patent ID: 6239994
Filing Date: 2001-05-29
Classification: H02M,Y02B

Abstract:
A switching power converter comprising:a secondary side transformer winding having first and second ends across which an AC voltage is inducible;a first regulation circuit including: a first switching element having a power terminal coupled to the first end of the secondary side transformer winding and another power terminal coupled to a first intermediate node; a second switching element having a power terminal coupled to the first intermediate node and another power terminal coupled to a common node; and a first inductor coupled from the first intermediate node to a first output node;a second regulation circuit including: a third switching element having a power terminal coupled to the second end of the secondary side transformer winding and another power terminal coupled to a second intermediate node; a fourth switching element having a power terminal coupled to the second intermediate node and another power terminal coupled to the common node; and a second inductor coupled from the second intermediate node to a second output node; anda control circuit operable to deliver respective drive signals to respective control terminals of the first, second, third, and fourth switching elements such that the switching elements turn on and off in such a manner that first and second regulated voltages appear between the first and second output nodes and the common node, respectively;the control circuit being operable to produce the drive signals such that the switching elements define at least three states, a first state being when the first, third and fourth switching elements are on and the second switching element is off, a second state being when the first and third switching elements are off and the second and fourth switching elements are on, and a third state being when the first, third and second switching elements are on and the fourth switching element is off.