Battery Charger and Step-Down
Converter for Portable Applications
Typical Characteristics – Step-Down Converter
Output Voltage Error vs. Temperature
(V
IN
= 3.6V; V
OUT
= 1.8V; I
OUT
= 250mA)
3.0
10.0
2.0
1.0
0.0
-1.0
-2.0
-3.0
-40
8.0
AAT2556
Switching Frequency Variation
vs. Temperature
(V
IN
= 3.6V; V
OUT
= 1.8V)
Output Error (%)
Variation (%)
-20
0
20
40
60
80
100
6.0
4.0
2.0
0.0
-2.0
-4.0
-6.0
-8.0
-10.0
-40
-20
0
20
40
60
80
100
°
Temperature (°C)
°
Temperature (°C)
Frequency Variation vs. Input Voltage
(V
OUT
= 1.8V)
2.0
No Load Quiescent Current vs. Input Voltage
50
Frequency Variation (%)
Supply Current (µA)
1.0
0.0
-1.0
-2.0
-3.0
-4.0
45
40
35
30
25
20
15
10
2.7
3.1
3.5
3.9
4.3
4.7
5.1
5.5
85°C
25°C
-40°C
2.7
3.1
3.5
3.9
4.3
4.7
5.1
5.5
Input Voltage (V)
Input Voltage (V)
P-Channel R
DS(ON)
vs. Input Voltage
1000
900
750
N-Channel R
DS(ON)
vs. Input Voltage
120°C
100°C
700
R
DS(ON)H
(mΩ)
Ω
R
DS(ON)L
(mΩ)
Ω
800
700
600
500
400
300
2.5
3.0
3.5
4.0
85°C
650
600
550
500
450
400
350
300
120°C
100°C
85°C
25°C
25°C
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
4.5
5.0
5.5
6.0
Input Voltage (V)
Input Voltage (V)
2556.2006.05.1.0
7
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
