US Patent 7889518 Half-bridge power converter system and method of operation

In one embodiment, a power converter generates an output voltage by modulating an input voltage according to operations of a first switch and a second switch connected in a half-bridge arrangement. The power converter includes a switch driver circuit for controlling the turning on and off of the first and second switches. A PWM controller generates a switch driver control signal for controlling the switch driver circuit according to an output voltage. The switch driver circuit generates an on-time control signal for turning off the first switch when the first switch has been turned on for longer than a threshold period.