NCP1200A

http://onsemi.com

2

Figure 1. Typical Application Example

EMI

FILTER

UNIVERSAL

INPUT

+

+

NCP1200A

+

Adj

FB

CS

GND

HV

Drv

1

2

3

4

8

7

6

5

*

*Please refer to the application information section

PIN FUNCTION DESCRIPTION

Pin No.

Pin Name

Function

Pin Description

1

Adj

Adjust the skipping peak current

This pin lets you adjust the level at which the cycle skipping process takes

place. Shorting this pin to ground, permanently disables the skip cycle

feature.

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.

3

CS

Current sense input

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

via an L.E.B.

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.

7

NC

−

This unconnected pin ensures adequate creepage distance.

8

HV

Connected to the high−voltage rail, this pin injects a constant current into