NCP1050, NCP1051, NCP1052, NCP1053, NCP1054, NCP1055

http://onsemi.com

2

Figure 1. Typical Application

Regulator Circuit

Fault Detector

Power

Switch

Circuit

Oscillator &

Gating Logic

Control Input

Power Switch Circuit Output

3, 7−8

1

2

5

+

Snubber

+

+

+

−

Converter

DC Output

AC Line

Input

Ground

Pin Function Description

Pin

(SOT−223)

Pin

(DIP−8)

Function

Description

1

1

This is the positive supply voltage input. During startup, power is supplied to this input

connected to this pin programs fault timing and frequency modulation rate.

2

2

Control Input

The Power Switch Circuit is turned off when a current greater than approximately

50

mA is drawn out of or applied to this pin. A 10 V clamp is built onto the chip to

protect the device from ESD damage or overvoltage conditions.

4

3, 7, 8

Ground

This pin is the control circuit and Power Switch Circuit ground. It is part of the

integrated circuit lead frame.

−

4

No Connection

3

5

Power Switch

Drain

This pin is designed to directly drive the converter transformer primary, and internally

connects to Power Switch and Startup Circuit.