PRODUCT DATASHEET
AAT1239-1
SwitchReg
TM
Typical Characteristics
(10 White LEDs; R
BALLAST
= 30.1Ω)
Ω
80
78
78
76
40V Step-Up Converter for 4 to 10 White LEDs
Efficiency vs. LED Current
Efficiency vs. LED Current
(9 White LEDs; R
BALLAST
= 30.1Ω)
Ω
V
IN
= 5V
Efficiency (%)
76
74
72
70
68
66
2
Efficiency (%)
V
IN
= 5V
74
72
70
68
66
V
IN
= 4.2V
V
IN
= 3.6V
V
IN
= 4.2V
4
6
8
V
IN
= 3.6V
10
12
14
16
18
20
2
4
6
8
10
12
14
16
18
20
I
LED
(mA)
I
LED
(mA)
Shutdown Current vs. Input Voltage
(EN = GND)
Input Voltage (top) (V)
Output Voltage (middle) (V)
1.0
(10 White LEDs; R
BALLAST
= 30.1Ω)
Ω
Feedback Voltage (bottom) (V)
4.2V
3.6V
33.2
33
32.8
0.62
0.6
0.58
Line Transient
Shutdown Current (µA)
0.8
0.6
0.4
0.2
0.0
2.7
3.1
3.5
3.9
4.3
4.7
25°C
85°C
-40°C
5.1
5.5
Input Voltage (V)
Time (50µs/div)
Accuracy I
LED
vs. Input Voltage
(V
FB
= 0.6V; R
BALLAST
= 30.1Ω)
Ω
2.0
1.5
1.5
Accuracy I
LED
vs. Temperature
(V
FB
= 0.6V; R
BALLAST
= 30.1Ω)
Ω
Accuracy I
LED
(%)
1.0
0.5
0.0
-0.5
-1.0
-1.5
-2.0
2.7
3.2
3.7
4.2
4.7
Accuracy I
LED
(%)
-40°C
1.0
0.5
0.0
-0.5
-1.0
-1.5
-40
25°C
85°C
5.2
5.7
-15
10
35
60
85
Input Voltage (V)
Temperature (°C)
1239-1.2008.06.1.1
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