Datasheet

ADM8845
Rev. C | Page 7 of 20
0
4
8
12
16
20
04867-0-010
DUTY CYCLE (%)
LED CURRENT (mA)
0 20 60 1008040
Figure 9. I
LED
(mA) vs. PWM Dimming (Varying Duty Cycle),
Six LEDs Enabled, Frequency = 1 kHz
0
50
100
150
250
300
04867-0-011
SUPPLY VOLTAGE (V)
SUPPLY CURRENT I
CC
(mA)
2.6 3.0 3.8 4.64.23.4
20mA/LED
15mA/LED
200
5.0 5.4
Figure 10. Input Current vs. Supply Voltage,
Six LEDs Enabled
04867-0-012
CH2 20.0mVCH1 20.0mV M 400ns CH1 220mV
2
1
B
W
B
W
V
OUT
V
CC
Figure 11. 1.5× Mode Operating Waveforms
60
65
70
80
90
95
04867-0-013
DUTY CYCLE (%)
EFFICIENCY (%)
0 40 60 807050
85
90 100
10 20
30
75
Figure 12. LED Efficiency vs. Varying Duty Cycle of 1 kHz PWM Signal,
Six LEDs Enabled, 20 mA/LED
04867-0-014
CH2 160mACH1 2.00V M 5.00µs CH2 180mV
2
1
B
W
B
W
CURRENT
3
V
OUT
CTRL1/2
CH3 1.00V
Figure 13. Soft Start Showing the Initial In-Rush Current and V
OUT
Variation,
Six LEDs @ 20 mA/LED, V
CC
= 3.6 V
04867-0-015
CH2 20.0mVCH1 20.0mV M 400ns CH1 220mV
2
1
B
W
B
W
V
OUT
V
CC
Figure 14 .2× Mode Operating Waveform