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Ver1.0
11
LD1016
16 CHANNEL CONSTANT CURRENT LED DRIVERS
APPLICATION GUIDE
6K7K 9K 10K 15K
20K
30K
60K
100
90
80
70
60
50
40
30
20
10
0
R
EXT -IOUT
Resistance of the external resister REXT in W
V
DS = 1.0V
R
EXT
I
OUT
9
k
Ω
60mA
11
k
Ω
50mA
14
k
Ω
40mA
19
k
Ω
30mA
29
k
Ω
20mA
59
k
Ω
10mA
7
k
Ω
75mA
6
k
Ω
85mA
Adjusting Output Current
The output current of each channel (IOUT) is set by an external resistor REXT. The relationship between IOUT
and REXT is shown in the following figure.
Also, the output current can be calculated from the equation:
VR-EXT = 1.2V ; Internal resistance RINT = 1KΩ
I
OUT = [VR-EXT / (REXT + RINT )] X 480
where REXT is the resistance of the external resistor connected to REXT terminal and VR-EXT is the
voltage of REXT terminal. The magnitude of current (as a function of REXT) is around 40mA at 14KΩ
and 20mA at 29K
Ω
Constant Current
In LED display application, LD1016 provides nearly no variation in current from channel to channel and
IC to IC. This can be achieved by:
1)
The maximum current variation between channels is less than ±3%, and that between ICs is less
than ±6%.
2)
In addition, the current characteristic of output stage is flat. The output current can be kept
constant regardless of the variations of LED forward voltage. This perform as a perfection of load
regulation.