PRODUCT DATASHEET
AAT2689
TM
SystemPower PMIC Solution for 12V Adapter Systems with 2-Output High Performance Step-Down Converters
Typical Characteristics
Step-Down Converter Efficiency vs. Load
Step-Down Converter DC Regulation
(VOUT1 = 3.3V; L = 4.7µH)
(VOUT1 = 3.3V; L = 4.7µH)
2.0
1.5
100
90
80
70
60
50
40
30
20
10
0
1.0
0.5
0.0
VIN1 = 6V
IN1 = 8V
VIN1 = 12V
VIN1 = 18V
VIN1 = 24V
VIN1 = 6V
-0.5
-1.0
-1.5
-2.0
V
VIN1 = 8V
VIN1 = 12V
VIN1 = 18V
VIN1 = 24V
0.1
1
10
100
1000
10000
0.1
1
10
100
1000
10000
Output Current (mA)
Output Current (mA)
Step-Down Converter Line Regulation
Step-Down Converter Output Ripple
(VOUT1 = 3.3V; L = 4.7µH)
(VIN1 = 12V; VOUT1 = 3.3V; IOUT1 = 1mA)
1.00
0.75
0.50
0.25
0.00
-0.25
-0.50
-0.75
-1.00
12V
0V
0.4
0.2
0.0
IOUT1 = 0.1mA
IOUT1 = 1mA
3.31
IOUT1 = 1250mA
IOUT1 = 2500mA
3.30
3.29
6
8
10
12
14
16
18
20
22
24
Input Voltage (V)
Time (2µs/div)
Step-Down Converter Output Ripple
Step-Down Converter Load Transient Response
(IOUT1 = 1.875A to 2.5A; VIN1 = 12V;
(VIN1 = 12V; VOUT1 = 3.3V; IOUT1 = 2.5A)
VOUT1 = 3.3V; COUT1 = 2x22µF)
3.0
12V
2.5A
2.5
0V
2.0
4.0
3.0
2.0
1.875A
1.5
3.4
3.3
3.2
3.32
3.30
3.28
Time (1µs/div)
Time (100µs/div)
w w w . a n a l o g i c t e c h . c o m
2689.2008.06.1.0
5
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