Datasheet

ADM8843
Rev. C | Page 14 of 16
USING SMALLER CAPACITOR VALUES
The ADM8843 can be operated with the smaller capacitor values described here to reduce capacitor footprint sizes.
Option 1
Input and output ripple plots for 1× and 1.5× modes of operation
are shown with C1, C2 = 0.22 μF; C3 = 0.47 μF; and C4 = 1 μF.
05050-026
CH2 10.0mV
CH3 10.0mV
M 400ns CH3 –33mV
3
2
B
W
B
W
V
OUT
V
CC
Figure 26. 1× Mode Operation, Four LEDs with 20 mA/LED at V
CC
= 5.0 V,
with a 1 μF V
CC
Decoupling Capacitor
05050-027
CH2 20.0mV M 400ns CH3 –33mV
3
2
B
W
V
OUT
V
CC
CH3 50.0mV
B
W
Figure 27. 1.5× Mode Operation, Four LEDs with 20 mA/LED at V
CC
= 3.6 V,
with a 1 μF V
CC
Decoupling Capacitor
Option 2
Input and output ripple plots for 1× and 1.5× modes of operation
are shown with C1, C2 = 0.22 μF; C3 = 0.47 μF; and C4 = 4.7 μF.
05050-028
CH2 10.0mV
CH3 10.0mV
M 1.00 μ s CH3 –33mV
3
2
B
W
B
W
V
OUT
V
CC
Figure 28. 1× Mode Operation, Four LEDs with 20 mA/LED at V
CC
= 5.0 V,
with a 4.7 μF V
CC
Decoupling Capacitor
05050-029
CH2 20.0mV
CH3 50.0mV
M 400ns CH3 –33mV
3
2
B
W
B
W
V
OUT
V
CC
Figure 29. 1.5× Mode Operation, Four LEDs with 20 mA/LED at V
CC
= 3.6 V,
with a 4.7 μF V
CC
Decoupling Capacitor