A controller for use in a power converter includes a control circuit coupled to generate a low side drive signal to control switching of a low side switch, and generate an ON signal and an OFF signal in response to a feedback signal representative of an output of the power converter. A high side signal interface circuit is coupled to generate a high side drive signal in response to the ON signal and the OFF signal to control switching of a high side switch. The ON signal and the OFF signal are coupled to be pulled up in response to a bypass voltage during an initial state. The high side signal is coupled to turn on the high side switch in response to the control circuit pulling the ON signal low, and turn off the high side switch in response to the control circuit pulling the OFF signal low.