Patent ID: 8278972

Claim:
A circuit for use in a half bridge converter, comprising: a high side switch coupled between a positive input terminal and a first terminal of a primary transformer winding; a low side switch coupled between a negative input terminal and the first terminal of the primary transformer winding; a first control circuit coupled to the high side switch, the positive input terminal and the first terminal of the primary transformer winding, the first control circuit coupled to sense a rate of voltage change with respect to time (dv/dt) across the high side switch while the high side switch is off to control the high side switch in response to the sensed rate of voltage change with respect to time (dv/dt) across the high side switch; and a second control circuit coupled to the low side switch, the first terminal of the primary transformer winding and the negative input terminal, the second control circuit coupled to sense a rate of voltage change with respect to time (dv/dt) across the low side switch while the low side switch is off to control the low side switch in response to the sensed rate of voltage change with respect to time (dv/dt) across the low side switch.