AAT2556
Battery Charger and Step-Down
Converter for Portable Applications
Typical Characteristics – Step-Down Converter
Efficiency vs. Load
(VOUT = 1.8V; L = 3.3µH)
DC Load Regulation
(VOUT = 1.8V; L = 3.3µH)
100
90
80
70
60
50
40
1.0
0.5
VIN = 5.0V
VIN = 2.7V
VIN = 3.6V
VIN = 3.6V
VIN = 5.5V
VIN = 5.5V
0.0
VIN = 2.7V
VIN = 4.2V
VIN = 5.0V
VIN = 4.2V
-0.5
-1.0
0.1
1
10
100
1000
0.1
1
10
100
1000
Output Current (mA)
Output Current (mA)
Efficiency vs. Load
(VOUT = 1.2V; L = 1.5µH)
DC Load Regulation
(VOUT = 1.2V; L = 1.5µH)
100
90
80
70
60
50
40
30
1.0
0.5
VIN = 2.7V
VIN = 5.0V
VIN = 3.6V
VIN = 5.5V
0.0
VIN = 5.5V
VIN = 5.0V
VIN = 4.2V
VIN = 3.6V
VIN = 4.2V
-0.5
-1.0
VIN = 2.7V
0.1
1
10
100
1000
0.1
1
10
100
1000
Output Current (mA)
Output Current (mA)
Soft Start
(VIN = 3.6V; VOUT = 1.8V;
OUT = 250mA; CFF = 100pF)
Line Regulation
(VOUT = 1.8V)
I
0.6
5.0
4.0
3.0
2.0
1.0
0.0
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0.0
-0.2
-0.4
0.5
0.4
VEN
IOUT = 0mA
IOUT = 50mA
0.3
0.2
IOUT = 150mA
0.1
-1.0
-2.0
-3.0
-4.0
-5.0
VO
0.0
-0.1
-0.2
-0.3
IOUT = 10mA
IOUT = 250mA
IL
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
Time (100µs/div)
Input Voltage (V)
6
2556.2006.05.1.0
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
