Application Circuits

HT7939

Rev 1.10

8

November 3, 2009

H T 7 9 3 9

V I N

E N

S W

O V P

F B

1 0 m H

2 . 2 m F

R f b

0 . 7 7 W

G N D

4 . 7 m F

4 . 5 V ~ 5 . 5 V

1 N 5 8 1 9

1 3 S t r i n g s

1 0 k W

1 5 0 k W

V D C D i m m i n g

0 V ~ 3 . 3 V

Figure 15. Application Circuit for Dimming Control Using a DC Voltage

H T 7 9 3 9

V I N

E N

S W

O V P

F B

1 0 m H

2 . 2 m F

R f b

0 . 7 7 W

G N D

4 . 7 m F

4 . 5 V ~ 5 . 5 V

1 N 5 8 1 9

1 3 S t r i n g s

L : G S 5 4 - 1 0 0 K ( G A N G S O N G )

C 1 : G R M 2 1 B R 6 1 E 4 7 5 K A 1 2 L ( M U R A T A )

C 2 : G R M 2 1 B R 7 1 E 2 2 5 K A 7 3 L ( M U R A T A )

Figure 13. Application Circuits for Driving 39 WLEDs

H T 7 9 3 9

V I N

E N

S W

O V P

F B

1 0 m H

2 . 2 m F

R f b

0 . 7 7 W

G N D

4 . 7 m F

4 . 5 V ~ 5 . 5 V

1 N 5 8 1 9

1 3 S t r i n g s

P W M S i g n a l

Figure 14. Application Circuit for Dimming Control Using a PWM Logic Signal