The NCP1337 combines a true current mode modulator anda demagnetization detector which ensures full Borderline/CriticalConduction Mode in any load/line conditions together withminimum drain voltage switching (Quasi−Resonant operation).The transformer core reset detection is done internally, without usingany external signal, due to the Soxyless concept. The frequency isinternally limited to 130 kHz, preventing the controller to operateabove the 150 kHz CISPR−22 EMI starting limit.By monitoring the feedback pin activity, the controller enters skipmode as soon as the power demand falls below a predeterminedlevel. As each restart is softened by an internal Soft−Skip, and asthe frequency cannot go below 25 kHz, no audible noise can beheard.The NCP1337 also features an efficient protective circuitry which,in presence of an overcurrent condition, disables the output pulsesand enters a safe burst mode, trying to restart. Once the default hasgone, the device auto−recovers. Also included is a bulk voltagemonitoring function (known as brown−out protection), an adjustableoverpower compensation, and a VCC OVP. The controllerimmediately restarts after any of these conditions, unless the faulttimer has timed out. Finally, an internal 4.0 ms soft−start eliminatesthe traditional startup stress.