Recipient #118203 printed on 4/15/2008. This is a ONE-TIME copy. Updates will not be provided.

ta9687

CONFIDENTIAL

ta9687-DS-1.0

Page 8

REFERENCE APPLICATION CIRCUIT

Figure 2: Typical Application

VIN: 12V ~ 18V

ENA: 0V—1V Disable; 2V—5V Enable

VDDA: 4.75V – 5.25V

PWM: 3.3Vpp, 200Hz, 10% Min Brightness, 100% Max Brightness

R18

100K

PDR2

NDR2

C50

4.7u

R31

1K

CN2

1

2

3

4

6

5

VIN

VIN

GND

GND

ENA

PWM

PDRA

C24

0.1u

C63

22p

NDR1

C22

220p

C65

10p

U1

1

2

3

4

5

6

14

13

12

11

10

9

8

7

15

16

VSEN

SSTCMP

CT

RT1

GNDA

PDR2

ISEN

PWM

TIMER

VDDA

PDR1

NDR1

NDR2

GNDP

OVPT

ENA

VS2

ZD1

5.6v 5%

R63

3M

D19

DIODE

R26

5.1k

C38

470u/35V

C35

33n

AP4502

U6

1

2

3

4

5

6

7

8

C64

2.2n

R30

360

CN24

1

2

C20

10n

VS4

C62

10p

AP4502

U5

1

2

3

4

5

6

7

8

C27

0.047u

R16

270K

C36

0.1u

R20

5.1K

ENA

F1

3A

R72

20K

Q1

2N3904

ENA

R64

4.3K

PWM

VS1

D9

DIODE

R33

1K

R34

100K

C21

47n

VS4

PWM

R67

100K

R32

100K

VDDA

R69

2.2K

C39

10u

R66

4.3K

NDR1

PDR1

Confidential

Copyright 2007 O2 Micro

Inc.

All Rights Reserved

Patent Pending

VS3

R71

100K

VDDA

CN19

1

2

R70

2.2K

VS2

R65

3M

C26

0.047u

R19

5.1K

PDRB

R68

20K

VS3

D6

BAV70/SOT

CN22

1

2

D8

BAV70/SOT

D3

5.6V

NDR2

D17

BAV99/SOT

C25

1u

R17

100K

T22

VS1

PDRA

C66

22p

D4

5.6V

R15

84.5K

R14

1M

C23

1u

PDRB

C67

2.2n

D18

DIODE

C37

1n

CN23

1

2