The present invention discloses a PFC-PWM controller having interleaved switching.
A PFC stage generates a PFC signal for switching a PFC boost converter of a power
converter. A PWM stage generates a PWM signal for switching a DC-to-DC converter
of the power converter. The PFC-PWM controller includes a power manager for generating
a discharge current and a burst-signal. Under light-load conditions, the discharge
current decreases in proportion to a load of the power converter. The burst signal
is utilized to disable the PFC signal in a suspended condition for power saving.
A pulse width of the pulse-signal ensures a dead time to spread switching signals,
such as the PFC and PWM signals, and reduces switching noise. When the discharge
current decreases, the pulse width of the pulse-signal will increase and a frequency
of the pulse-signal will decrease correspondingly. This further reduces power consumption
under light-load and zero-load conditions.
