點晶科技股份有限公司

SILICON TOUCH TECHNOLOGY INC.

DD331

High CONSTANT CURRENT LED DRIVERS

Version:A.002

Page

6

Timing Diagram

ENG,ENR,ENB,ENW to GATER,GATEG,GATEB,GATEW

GATER

GATEG

GATEB

GATEW

ENG

ENR

ENB

ENW

50%

50%

50%

50%

Constant-Current Output

The constant-current value of each output channels is set by a N-type MOSFET and

an external resistor connected between the REXT(R, G, B, W) pin and GND individually.

Varying the resistor value can adjust the current. Notice that the output current is a little

increasing or decreasing until the device temperature and ambient temperature are

balance. Approximate output current value can be calculated by following equation:

Iout

5

10

20

40

80

160

220

M

883.1

967.2

990

10128

1044.6

1115.6

1478.8

Iout = 0.52 / Rext * M

0

10

20

30

40

50

60

70

80

90

100

0

50

100

150

200

Rext (Ω)