點晶科技股份有限公司

SILICON TOUCH TECHNOLOGY INC

.

新竹市科學園區展業一路9號7樓之1

9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.

Tel：886-3-5645656

Fax：886-3-5645626

3-CHANNEL CONSTANT CURRENT LED DRIVERS

Version:A.002

Page 8

DM413

Constant-Current Output

Constant-current value of each output channel is set by an external resistor connected between

the R(G、B)REX pin and GND individually. Varying the resistor value can adjust the current scale

ranging from 5mA to 100mA. The output current value is calculated roughly by the following

equation:

Iout(mA) ~

0.6 V

REX (ohm)

× 1000

Output Current as a Function of REX value

0

10

20

30

40

50

60

70

80

90

100

110

0

10

203040

506070

8090

100

110

120

REX (ohm)

Output Current as a Function of Output Voltage

0

10

20

30

40

50

60

70

80

90

100

110

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

1.8

2

2.2

2.4

2.6

2.8

3

Vout (volt)