Patent ID: 7831401

Claim:
An apparatus for detecting a power outage in an input of a switched mode power supply (SMPS), the SMPS comprising a switch that is coupled to a winding of a magnetic device, and a control signal coupled to the switch and operative to selectively open and close the switch, the apparatus comprising: a control signal detection module coupled to the control signal and operative to generate a detection signal dependent on the control signal; and a processing module operative to receive the detection signal, and further operative to process the detection signal to detect a power outage in the input of the SMPS dependent on the detection signal, wherein the processing module includes: a comparator operative to compare the detection signal with a reference signal; a load transient detection module operative to detect transients in a load of the SMPS; wherein the processing module is further operative to selectively adjust the reference signal dependent on an output of the load transient detection module.