NXP Semiconductors

15

34845

6

Typical applications

6.1

Application diagram

Figure 10. Typical application circuit for single wire control, fS = 600 KHz

(VIN = 9.0 V, ILED/channel = 20 mA/channel, 10 LEDs/channel, OVP = 35 V, VPWM = 3.3 V)

MC34845

CH5

CH1

CH2

CH3

33 uH

CH4

20

23

18

11

10

9

8

7

3

4

60 V, 1A

LED

LEG 2

VIN

LED

LEG 1

CH6

12

LED

LEG 3

SWA

SWB

LED

LEG 4

LED

LEG 5

LED

LEG 6

4.7 uF

OVP

14

FAIL

22

1

VIN

2.2uF

10 V

VD C1

2. 2uF

10 V

VD C2

EN

6

24

VOU T

PGN D

2

5

PGN D

WAKE

EP

10uf

25V

15

0.1 %

21

13

GND

GND

PWM

16

680KΩ

167KΩ

4.7 uF

100 pF

100pF

100 pF

100 pF

100 pF

100p F

0. 1uf

220pF

COM P

17

33nF

kO

10KΩ

Cont rol

Un it

3.3kΩ

/C

765KΩ

Caps should be located

as close as possible to the

MC34845 Device

7.65k

Ω