NCP1246 Datasheet - ON Semiconductor

NCP1246 Fixed Frequency Controller

Pin No 1 2 3 4 5 6 Pin Name LATCH FB CS GND DRV VCC Function LatchïOff Input Feedback + Shutdown pin Current Sense ï Drive output VCC input Pin Description Pull the pin up or down to latchïoff the controller. An internal current source allows the direct connection of an NTC for over temperature dete.

NCP1246 Product Preview Fixed Frequency Current Mode Controller for Flyback Converters The NCP1246 is a new fixedïfrequency currentïmode controller featuring the Dynamic SelfïSupply. This function greatly simplifies the design of the auxiliary supply and the VCC capacitor by activating the internal startup current source to supply the controller during startïup, transients, latch, standïby etc. This device contains a special HV detector which detect the application unplug from the AC input line .

NCP1246 Features

* a timerïbased fault detection that ensures the detection of overload and an adjustable compensation to help keep the maximum power independent of the input voltage. Due to frequency foldback, the controller exhibits excellent efficiency in light load condition while still achieving very low standby

NCP1246_ONSemiconductor.pdf