Abstract: A switching power converter includes a power circuit and a control circuit for receiving an analog signal representing a parameter of the power circuit. The control circuit includes an ADC for converting the analog signal into a digital signal, and a switch driver for generating a control signal for controlling a switch in the power circuit over multiple switching cycles. The control circuit is configured to adaptively determine a trigger point for activating the ADC within a switching cycle to sample the analog signal, and activate the ADC at the determined trigger point so a control parameter generated based on the digital signal is provided to the switch driver a minimal period of time before the next switching cycle begins. The adaptively determined trigger point optimizes phrase margin loss and bandwidth in the control circuit. Other example switching power converters and control circuits are also disclosed.

Abstract: A control circuit is configured to sense an AC input voltage of a power factor correction (PFC) power circuit in a switching power converter, provide a control signal having an on-time and an off-time to at least one power switch of the PFC power circuit, and in response to detecting a peak voltage of the AC input voltage, increase the on-time of the control signal based on the sensed AC input voltage during an interval that begins with the peak voltage of the AC input voltage and ends with the next zero crossing following the peak voltage of the AC input voltage to improve a power factor of the switching power converter. Other example switching power converters, PFC power circuits and control circuits for controlling one or more power switches are also disclosed.

Abstract: A control circuit is configured to sense an AC input voltage of a power factor correction (PFC) power circuit in a switching power converter, provide a control signal having an on-time and an off-time to at least one power switch of the PFC power circuit, and in response to detecting a peak voltage of the AC input voltage, increase the on-time of the control signal based on the sensed AC input voltage during an interval that begins with the peak voltage of the AC input voltage and ends with the next zero crossing following the peak voltage of the AC input voltage to improve a power factor of the switching power converter. Other example switching power converters, PFC power circuits and control circuits for controlling one or more power switches are also disclosed.