Patent ID: 6911848

Claim:
An apparatus for driving a control input of one or more power switching devices, comprising: a drive transformer having a secondary winding; a plurality of switches each having a control terminal referenced to a common signal reference for turning the switch ON and OFF and an output connected to drive the transformer; the plurality of switches including a first switch and a second switch being respectively poled to induce a magnetic flux in the drive transformer in a first and in a second direction when ON; the secondary winding being connected to drive the control inputs of the one or more power switching devices; a control circuit connected to the control terminals and configured to operate the first and second switches in a series of control cycles each characterized by: (a) two ON intervals during which one of the first and second switches is ON; (b) two OFF intervals during which both of the first and second switches is OFF and energy stored in the drive transformer is used to charge and discharge parasitic output capacitances of the plurality of switches and a parasitic input capacitance of the one or more power switching devices.