AP1688

Document number: DS36603 Rev. 2 - 2

2 of 10

www.diodes.com

February 2015

© Diodes Incorporated

AP1688

A Product Line of

Diodes Incorporated

Pin Descriptions

Pin Number

Pin Name

Function

1

NC

No connection

2

VS

Detects the negative terminal voltage of output.

3

VA

Detects the average value of the negative terminal voltage of output.

4

CS

Primary current sensing

5

FB

The feedback voltage sensing from the auxiliary winding

6

GND

Ground

7

OUT

Gate driver output

8

VCC

Supply voltage of gate driver and control circuits of the IC

Functional Block Diagram

VCC

OUT

CS

GND

FB

VS

Regulator

& Bias

S

RQ

ZCD

Detector

Input Current

Shaping and

Constant

Current Control

UVLO

OVP

pro

UVLO

-

+

COMP

ZCD

-

+

EA

0.1V

1.75V

Peak Current Control &

LEB

Driver

VA

R

S

4

5

2

3

6

7

8