NCP1252 Datasheet (ON Semiconductor)

NCP1252, PWM Controller

This pin directly connects to an optocoupler collector.

This pin monitors the input voltage image to offer a Brown *out protection.

Monitors the primary current and allows the selection of the ramp compensation amplitude.

A resistor connected to ground fixes the switching frequency.

The contr

Current Mode PWM Controller for Forward and Flyback Applications NCP1252 The NCP1252 controller offers everything needed to build cost effective and reliable ac dc switching supplies dedicated to ATX power supplies.

Thanks to the use of an internally fixed timer, NCP1252 detects an output overload without relying on the auxiliary Vcc.

A Brown Out input offers protection against low input voltages and improves the converter safety.

Finally a SOIC 8 package saves P

NCP1252 Features

* Peak Current Mode Control

* Adjustable Switching Frequency up to 500 kHz

* Jittering Frequency 5% of the Switching Frequency

* Latched Primary Over Current Protection with 10 ms Fixed Delay

* Delay Extended to 150 ms in E Version

* Delayed Operation Upon Start

* up v