In one form, a power factor correction (PFC) controller, comprising includes a regulation circuit, a dead-time detection circuit, and a pulse width modulator. The regulation circuit provides a control voltage in response to a feedback voltage received at a feedback input terminal, wherein the feedback voltage is proportional to an output voltage. The dead-time detection circuit has an input coupled to a zero current detection input terminal, and an output for providing a dead-time signal. The pulse width modulator is responsive to the control voltage and the dead-time signal to provide a drive signal that controls conduction of a switch to improve a power factor of an offline converter, wherein the pulse width modulator modulates both an on-time and a switching period of the drive signal using the dead-time signal in a discontinuous conduction mode.