A power converter controller includes a high side signal interface circuit that includes a common mode cancellation circuit that is coupled to generate a fourth current signal representative of an OFF signal referenced to a bypass voltage during an initial state, and a first current signal in response to an ON signal being pulled to a lower value relative to the OFF signal to turn ON a high side switch. The common mode cancellation circuit generates a common mode rejection signal in response to the first and fourth current signals. A first current hysteresis comparator receives the first and fourth current signals, the common mode rejection signal, and a drive signal to generate a first output signal. A drive signal generated in response to the first output signal in a presence of a common mode voltage caused by slewing at a half bridge node.