點晶科技股份有限公司

SILICON TOUCH TECHNOLOGY INC

.

16-bit Constant Current LED Driver with Error Detection

Version:A.001

Page 11

未經授權而逕予重製、複製、使用或公開本文件，行為人得被追究侵權之相關民刑事責任

Unauthorized reproduction, duplication, use or disclosure of this document will be deemed as infringement.

DM137

Constant-Current Output

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

the REXT pin and GND. The current scale ranging can be adjusted from 5mA to 90mA by varying

the resistor value. The reference voltage of REXT terminal (Vrext) is approximately 0.6V. The

output current value is calculated by the following equation:

Iout(mA)

5

10

20

30

40

50

60

70

80

90

M

99.7

98.1

96.0

94.2

92.5

90.8

89.1

87.1

85.1

84.4

Output Current as a Function of Rrext value

0

10

20

30

40

50

60

70

80

90

100

01

23

45

678

9

10

11

12

Rrext (KΩ)

Output Current as a Function of Output Voltage

0

10

20

30

40

50

60

70

80

90

100

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 (V)

In order to obtain a good performance of constant-current output, a suitable output voltage is

necessary. Users can get related information about the minimum output voltage above.

Iout (mA) ~

× M