Datasheet

ADD5205 Data Sheet
Rev. 0 | Page 8 of 16
TYPICAL PERFORMANCE CHARACTERISTICS
0
10
20
30
40
50
60
70
80
90
100
0510
INPUT VOLTAGE (V)
BOOST CONVERTER EFFICIENCY (%)
15 20
0
9858-004
0
5
10
LED CURRENT (mA)
15
20
25
0510
INPUT VOLTAGE (V)
15 20
09858-007
Figure 4. Boost Converter Efficiency vs. Input Voltage,
I
LED
= 20 mA, Brightness = 100%, and LEDs = 6 Series × 4 Parallel
Figure 7. LED Current vs. Input Voltage (I
LED
= 22 mA)
0
5
10
LED CURRENT (mA)
15
25
20
30
0 400 800
R
SET
(kΩ)
1200
1400200 600 1000 1600
09858-005
–20
–15
–10
–5
0
5
10
15
20
02040
PWM INPUT DUTY CYCLE (%)
LED CURRENT M
A
TCHING (%)
60 80 100
09858-008
Figure 8. LED Current Matching vs. PWM Input Duty Cycle
Figure 5. LED Current (I
LED
) vs. R
SET
09858-009
V
IN
= 3.7V
BRIGHTNESS = 100% 6 SERIES x 4 PARALLEL
A CH3 960mV
1
2
4
3
V
OUT
(10V/DIV)
SHDN (3V/DIV)
I
L
(500mA/DIV)
V
SW
(10V/DIV)
0
20
18
16
14
12
10
LED CURRENT (mA)
8
6
4
2
0
20 40
PWM INPUT DUTY CYCLE (%)
60 80 100
09858-006
Figure 6. LED Current vs. PWM Input Duty Cycle
Figure 9. Start-Up Waveforms (Brightness = 100%)