PRODUCT DATASHEET
AAT1231
SwitchReg
TM
Step-Up DC/DC Converters for White LED Backlight Applications
Typical Characteristics
Accuracy I
LED
vs. Temperature
(V
FB
= 0.6V; R
BALLAST
= 30.1Ω)
Ω
1.0
0.8
2.0
1.5
Accuracy I
LED
vs. Input Voltage
(V
FB
= 0.6V; R
BALLAST
= 30.1Ω)
Ω
Accuracy I
LED
(%)
0.5
0.3
0.0
-0.3
-0.5
-0.8
-1.0
-40
-15
10
35
60
85
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
-40°C
25°C
85°C
4.7
5.2
5.7
Temperature (°C)
Input Voltage (V)
Line Transient
(6 White LEDs; R
BALLAST
= 30.1Ω)
Feedback Voltage (bottom) (V)
Enable Voltage (V) (top)
Feedback Voltage (V) (middle)
Input Voltage (top) (V)
Output Voltage (middle) (V)
2.5V
0V
0.6
0.4
0.2
0
Shutdown
(V
FB
= 0.6V; I
LED
= 20mA)
Inductor Current (A) (bottom)
4.2V
20.8
20.6
20.4
20.2
0.8
0.6
0.4
3.6V
0.5
0.0
Time (50µs/div)
Time (50µs/div)
Output Ripple
(6 White LEDs; I
LED
= 13mA)
V
OUT
(DC
Offset 19.8V)
(50mV/div)
20
Output Ripple
(6 White LEDs; I
LED
= 20mA)
V
OUT
(DC
Offset 20.7V)
(20mV/div)
V
LX
(V)
0
V
LX
(V)
20
0
0.5
0.5
I
L
(A)
0
I
L
(A)
0
Time (400ns/div)
Time (200ns/div)
6
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1231.2008.06.1.5
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