AAT1239-1_0810 Datasheet, PDF (21/23 Pages) Advanced Analogic Technologies – 40V Step-Up Converter for 4 to 10 White LEDs

SwitchReg^TM
PRODUCT DATASHEET
AAT1239-1
40V Step-Up Converter for 4 to 10 White LEDs
Additional Applications
Li-Ion
VIN = 2.7V
to 5.5V
C1
2.2μF
PVIN
LIN
VIN
SW
AAT1239-1
OVP
PGND
EN/SET
FB
SEL
AGND
L1
2.2μH
DS1
Schottky
R2
158k
R3
12k
Up to 17V/
30mA max
D1
LED
D2
C2
LED
2.2μF
D3
LED
D4
LED
R1
30.1Ω
20mA
Efficiency vs. LED Current
(4 White LEDs; R_BALLAST = 30.1Ω)
84
83
V_IN = 5V
82
81
80
79
78
V_IN = 4.2V
V_IN = 3.6V
77
76
75
74
2
4
6
8
10 12 14 16 18 20
I_LED (mA)
Figure 12: Four LEDs In Series Configuration.
Li-Ion
VIN = 2.7V
to 5.5V
C1
2.2μF
PVIN
LIN
VIN
SW
AAT1239-1
OVP
PGND
EN/SET
FB
SEL
AGND
L1
2.2μH
DS1
Schottky
R2
287k
R3
12k
Up to 30V/
30mA max
D1
LED
D2
C2
LED
2.2μF
D3
LED
D4
LED
D5
LED
R1
30.1Ω
20mA
D8 D7 D6
LED LED LED
Efficiency vs. LED Current
(8 White LEDs; R_BALLAST = 30.1Ω)
80
78
V_IN = 5V
76
74
72
V_IN = 4.2V
V_IN = 3.6V
70
68
66
2
4
6
8
10 12 14 16 18 20
I_LED (mA)
Figure 13: Eight LEDs In Series Configuration.
Li-Ion
VIN = 2.7V
to 5.5V
C1
2.2μF
PVIN
LIN
VIN
SW
AAT1239-1
OVP
PGND
EN/SET
FB
SEL
AGND
L1
2.2μH
DS1
Schottky
R2
324k
R3
12k
Up to 34V/
30mA max
D1
LED
D2
C2
LED
2.2μF
D3
LED
D4
LED
D5
LED
R1
30.1Ω
20mA
D9 D8 D7 D6
LED LED LED LED
Efficiency vs. LED Current
(9 White LEDs; R_BALLAST = 30.1Ω)
78
V_IN = 5V
76
74
72
70
V_IN = 4.2V
V_IN = 3.6V
68
66
2
4
6
8
10 12 14 16 18 20
I_LED (mA)
Figure 14: Nine LEDs In Series Configuration.
1239-1.2008.10.1.2
www.analogictech.com
21