Power controller with smooth transition to pulse skipping

摘要

A power converter control circuit includes a ramp signal circuit, a blanking circuit, and a pulse driver circuit. The ramp signal circuit provides a ramp signal in response to a power converter feedback signal and an enable signal. The blanking circuit provides a blanking signal in response to the ramp signal and a clock signal. The blanking signal is provided when both the ramp signal is increasing in value and the enable signal indicates a light load operating condition. The pulse driver circuit provides a power switch control pulse in accordance with the clock signal and in the absence of the blanking signal.

主权项

1. A power converter control circuit comprising:
a ramp circuit coupled to provide a ramp signal in response to a power converter feedback signal and an enable signal; a blanking circuit coupled to provide a blanking signal in response to the ramp signal and a clock signal, wherein the blanking signal is provided when the ramp signal is increasing in value and the enable signal indicates a light load operating condition; and a pulse driver circuit coupled to control switching of a power switch of the power converter in accordance with the clock signal, wherein the pulse driver circuit is further coupled to provide a drive signal to enable switching of the power switch in the absence of the blanking signal and to disable switching of the power switch in the presence of the blanking signal.