Diodes AL8808 - Manual (Page 7)

AL8808
Document number: DS35648 Rev. 2 - 2
7 of 20
www.diodes.com
January 2013
© Diodes Incorporated
NEW PROD
UC
T
AL8808
Typical Performance Characteristics
(670mA LED Current; T
A
= +25°C unless otherwise stated.)
18 6 9 12 15 21 24 27 30
INPUT VOLTAGE (V)
Figure 20. LED Current Deviation vs. Input Voltage
DE
VIA
T
IO
N F
R
O
M
TA
R
G
E
T
C
U
R
R
EN
T
(%)
5
3
-3
-5
1
-1
4 LEDs
5 LEDs
7 LEDs
1 LED
2 LEDs
3 LEDs
T = 25°C,
L = 33µH
R
= 150m
A
SET
Ω
18 6 9 12 15 21 24 27 30
INPUT VOLTAGE (V)
Figure 21. Switching Frequency vs. Input Voltage
SW
IT
C
H
IN
G
F
R
E
Q
U
E
N
C
Y
(k
H
z)
500
400
100
0
300
200
800
700
600
4 LEDs 5 LEDs
7 LEDs
1 LED
2 LEDs 3 LEDs
T = 25°C,
L = 33µH
R
= 150m
A
SET
Ω
18 6 9 12 15 21 24 27 30
INPUT VOLTAGE (V)
Figure 22. LED Current Deviation vs. Input Voltage
DEVI
A
T
IO
N F
R
O
M
TA
R
G
E
T
(%)
2
1
-2
-5
0
-1
5
4
3
-4
-3
4 LEDs
5 LEDs
7 LEDs
1 LED
2 LEDs
3 LEDs
T = 25°C,
L = 68µH
R
= 150m
A
SET
Ω
18 6 9 12 15 21 24 27 30
INPUT VOLTAGE (V)
Figure 23. Switching Frequency vs. Input Voltage
SW
IT
C
H
IN
G
F
R
E
Q
U
E
N
C
Y
(k
H
z)
300
250
50
0
200
150
450
400
350
100
T = 25°C,
L = 100µH
R
= 150m
A
SET
Ω
4 LEDs 5 LEDs
7 LEDs
1 LED
2 LEDs
3 LEDs
18 6 9 12 15 21 24 27 30
INPUT VOLTAGE (V)
Figure 24. LED Current Deviation vs. Input Voltage
DEVI
A
T
IO
N
F
R
O
M T
A
R
G
ET (
%
)
2
1
-2
-5
0
-1
5
4
3
-4
-3
18 6 9 12 15 21 24 27 30
INPUT VOLTAGE (V)
Figure 25. Switching Frequency vs. Input Voltage
SW
IT
C
H
IN
G
F
R
E
Q
U
EN
C
Y
(k
H
z)
150
0
100
250
200
50