Minimum dutycycle for TOP254EN

1 post / 0 new

At zero output power for a 25W flyback power supply, the TOP254EN goes into hick-up mode because the minimum on-time for the switch seems to be about 1us. The frequency is set at 66kHz. The hick-up mode may cause acoustic noise, we like to avoid this. Is the 1us on-time part of the TOP254EN characteristics, or may it be caused by time-lags in the feedback circuit.