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ILD8150 80 V high side buck LED driver IC with hybrid dimming
Circuit description
2.2.3
Dimming
Input dimming signal is PWM with minimal amplitude V
dimming is high enough, and so is the feedback speed, that any input voltage change does not affect output
current (no flicker). The IC operates in hybrid dimming mode. The dimming curve is shown in Figure 6, which
eliminates color shift and audible noise. In the range from 12.5 to 100 percent it operates in analogue dimming
mode as shown in Figure 5, and from 0.5 to 12.5 percent in PWM mode as shown in Figure 4, with fixed output
frequency f
.
out
I
[A]
OUT
I
LED,AVG
t
PWM _OUT,ON
PWM dimming
Figure 4
I
OUT
Analog dimming
Figure 5
Hybrid dimming curve
Figure 6
Application Note
1/f
OUT
[A]
LED,AVG
LED,AVG
100 x I
/I
out
ref
[%]
100
Analog dim ming
12.5
Hybrid dimming
0.5
0.5
12.5
with frequency f
DIM
1/f
t
t
SW
ON
OFF
100
6 of 28
. Current accuracy over
DIM_input
time [s]
time [s]
D
PWM _IN
[%]
V 1.0
2019-01-23
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