US Patent 10491126 Closed loop foldback control

A controller for use in a power converter includes comparator coupled to generate a regulation signal in response to a regulation reference and an output sense signal. The output sense signal is representative of an output of the power converter. A drive signal generator is coupled to the comparator to generate a drive signal to control switching of a power switch of the power converter in response to the regulation signal. The drive signal generator is further coupled to generate an operation sense signal representative of an operational state of the power switch. A foldback control is coupled to the comparator and the drive signal generator to generate the regulation reference in response to the regulation signal and the operation sense signal.