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16-channel 12-bit PWM Constant Current LED Driver

Version:A.003

Page 9

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DM631

Constant-Current Output

Constant-current value(Iout

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 1.23V.

The output current value is calculated by the following equation:

Iout(mA)

5

10

20

30

40

50

60

70

80

90

M

50.40

49.38

49.16

48.40

47.60

46.72

45.03

44.32

43.62

42.69

O utput C urre nt a s a Func tiono R e xt va lue

0

10

20

30

40

50

60

70

80

90

100

0

1

2

3

4

5

6

7

8

9

10

11

12

13

Re xt(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