NCP1239 Switching Controllers

onsemi NCP1239 Switching Controllers are fixed-frequency current-mode controllers featuring a high-voltage start-up current source to provide a quick and lossless power-on sequence. This function greatly simplifies the design of the auxiliary supply and the V_CC capacitor. These NCP1239 controllers feature a timer-based fault detection circuitry that ensures a quasi-flat overload detection, independent of the input voltage. Typical applications include AC-DC converters for TVs, set-top boxes, and printers offline adapters for notebooks and netbooks.