New prod uc t al8808, Typical performance, Al8808 – Diodes AL8808 User Manual
Page 6: Characteristics
AL8808
Document number: DS35648 Rev. 2 - 2
6 of 20
January 2013
© Diodes Incorporated
NEW PROD
UC
T
AL8808
Typical Performance
Characteristics
(L = 68µH, T
A
= +25°C, unless otherwise stated.)
6
9
12
15
18
21
24
27
30
INPUT VOLTAGE (V)
Figure 14. Efficiency vs. Input Voltage
100
95
90
85
80
75
70
EFF
IC
IE
N
C
Y
(%
)
1 LED
2 LEDs
3 LEDs
4 LEDs 5 LEDs
7 LEDs
T = 25°C
L= 68µH
R
= 150m
A
SET
Ω
1 LED
2 LEDs
3 LEDs 4 LEDs
5 LEDs
7 LEDs
6
9
12
15
18
21
24
27
30
INPUT VOLTAGE (V)
Figure 15. 330mA LED Current vs. Input Voltage
0.36
0.35
0.34
0.33
0.32
0.31
0.30
LE
D
C
U
R
R
E
N
T
(A
)
T = 25°C
L= 68µH
R
= 300m
A
SET
Ω
6
9
12
15
18
21
24
27
30
INPUT VOLTAGE (V)
Figure 16. Switching Frequency vs. Input Voltage
450
400
300
200
100
50
0
SW
IT
C
H
IN
G
F
R
E
Q
U
EN
C
Y
(k
H
z)
350
250
150
1 LED
2 LEDs 3 LEDs 4 LEDs 5 LEDs
7 LEDs
6
9
12
15
18
21
24
27
30
INPUT VOLTAGE (V)
Figure 17. 670mA LED Current vs. Input Voltage
0.74
0.72
0.70
0.66
0.64
0.62
0.60
LE
D
C
U
R
R
EN
T
(A
)
0.68
T = 25°C, V
L= 68µH, R
= 150m
A
SET
IN
= 12V
Ω
1 LED
2 LEDs 3 LEDs
4 LEDs
5 LEDs
7 LEDs
6
9
12
15
18
21
24
27
30
INPUT VOLTAGE (V)
Figure 18. Duty Cycle vs. Input Voltage
100
90
70
40
20
10
0
D
U
T
Y
C
Y
C
LE
(
%
)
80
60
30
50
1 LED
2 LEDs
3 LEDs
4 LEDs
5 LEDs
7 LEDs
T = 25°C
L= 68µH
R
= 150m
A
SET
Ω
6
9
12
15
18
21
24
27
30
INPUT VOLTAGE (V)
Figure 19. 1A LED Current vs. Input Voltage
1 LED
2 LEDs
3 LEDs
4 LEDs
5 LEDs
7 LEDs
T = 25°C
L= 68µH
R
= 100m
A
SET
Ω
1.10
1.05
0.95
0.90
LE
D
C
U
R
R
EN
T
(A
)
1.00