AP3981C

Document number: DS41619 Rev. 2 - 2

2 of 16

www.diodes.com

June 2019

© Diodes Incorporated

AP3981C

Typical Applications Circuit

AC

R1

C13

T1

D3

F1

R17

C3

C12

CY1

GND

DRAIN

SOURCE

VCC

AP3981C

U1

FB

VOUT

GND

C2

L1

5,6,7,8

4

1

R5

R6

2

R18

R2

D1

C1

DB1

B1

3

D3

R13

R16

R15

C10

R7

R9

C14

Pin Descriptions

Pin Number

Pin Name

Function

1

GND

The ground of the IC

2

FB

Connect to the auxiliary winding through a divider network, used as a multi-function pin to

realize output voltage sample for CV control, tONS detection for CC control, line voltage sense

for line compensation, and FB-negative-protection detection as well.

3

VCC

The power supply of the IC

4

SOURCE

SOURCE terminal of the integrated MOSFET

5, 6, 7, 8

DRAIN

DRAIN terminal of the integrated MOSFET