US Patent 11283343 Extremum locator with measurement enable circuit

A controller for use in a power converter for transferring energy between an input and an output, the controller comprising a second controller to generate a request event and a request signal in response to a feedback signal and a switching window signal, the second controller to transmit the request event during a switching window of the switching window signal. The second controller comprising an extremum locator switching window generator to generate the switching window corresponding with an extremum in the winding signal and a measurement enable circuit to output an enable signal to enable the extremum locator switching window generator to measure a duration of a half cycle to generate the switching window. The measurement enable circuit to enable the extremum locator switching window generator in response to the feedback signal reaching a percentage of a target reference and output a quiet signal to prevent transmitting the request event.