NCP1308

http://onsemi.com

2

Figure 1. Typical Application Schematic

1

8

2

3

4

6

5

7

NCP1308

+

Universal

Network

R*

+

12 V @ 1 A

GND

+

Y1 Type

*Please refer to the application information section.

PIN FUNCTION DESCRIPTION

Pin

Symbol

Function

Description

1

Dmg

Core reset detection

The auxiliary FLYBACK signal ensures discontinuous operation.

2

FB

Sets the peak current setpoint

By connecting an optocoupler to this pin, the peak current setpoint is adjusted

accordingly to the output power demand. By bringing this pin below the internal

skip level, the device shuts off.

3

CS

Current sense input and skip

cycle level selection

This pin senses the primary current and routes it to the internal comparator via an

LEB By inserting a resistor in series with the pin, you control the level at which the

skip operation takes place.

4

GND

The IC ground

−

5

Drv

Driving pulses

The driver’s output to an external MOSFET.

6

Supplies the IC

This pin is connected to an external bulk capacitor of typically 10

mF. If an auxiliary

winding brings this pin above 16 V typical, the circuit permanently latches off.

7

NC

−

This unconnected pin ensures adequate creepage distance.

8

HV

High−voltage pin

bulk capacitor.