Patent ID: 7830130

Claim:
A method of detecting an overload condition of a resonant discontinuous forward converter (RDFC), said converter including a transformer with primary and secondary matched polarity windings and a switch to, in operation, cyclically switch DC power to said primary winding of said transformer, said converter further having a DC output coupled to said secondary winding of said converter, said method comprising: sensing a primary winding signal during an on period of said switch, said primary winding signal representing an operational current in said primary winding; comparing said sensed primary winding signal with an overload threshold; and generating an overload signal for triggering an overload condition in said RDFC, said overload signal representing a period during which said sensed primary winding signal is greater than said overload threshold; the method further comprising: sensing a first event associated with switch on of said switch; sensing a second event associated with said overload signal; determining a duration between said first and second events; comparing said duration with an overload period threshold value; generating an early overload detection signal for detecting an early overload condition of said RDFC, said early overload detection signal being generated in response to said sensed duration being below said overload period threshold value.