NCP1251 Datasheet (ON Semiconductor) - Current-Mode PWM Controller

NCP1251, Current-Mode PWM Controller

The controller ground.

Hooking an optocoupler collector to this pin will allow regulation.

A resistive divider from the auxiliary winding to this pin sets the OPP compensation level.

When brought above 3 V, the part is fully latched off.

This pin monitors the primary peak current but also offers a m

DATA SHEET www.onsemi.com Current-Mode PWM Controller for Off-line Power Supplies NCP1251 The NCP1251 is a highly integrated PWM controller capable of delivering a rugged and high performance offline power supply in a tiny TSOP 6 package.

With a supply range up to 28 V, the controller hosts a jittered 65 kHz or 100 kHz switching circuitry operated in peak current mode control.

When the power on the secondary side starts to decrease, the controller automatically folds back its switching

NCP1251 Features

* Fixed

* Frequency 65 or 100 kHz Current

* Mode Control Operation

* Internal and Adjustable Over Power Protection (OPP) Circuit

* Frequency Foldback Down to 26 kHz and Skip

* Cycle in Light Load Conditions

* Internal Ramp Compensation

* Internal Fixed 4 ms Soft