Power Integrations, Inc.
SWITCHED MODE POWER CONVERTER CONTROLLER WITH RAMP TIME MODULATION

Abstract:

A controller to regulate a power converter includes a terminal that receives an enable signal including enable events representative of an output of the power converter. A drive circuit generates a drive signal to control switching of a power switch to control an energy transfer from an input to an output of the power converter. The drive circuit turns on the power switch when an enable event is received in the enable signal. A current limit threshold generator is coupled to the drive circuit to generate a threshold signal. The threshold signal increases in response to the power switch turning off and subsequently decreases. The threshold signal and a time between consecutive enable events are used to modulate the drive signal to regulate the output of the power converter.