High Efficiency, Low Noise, Fast Transient
400mA Step-Down Converter
Typical Characteristics
Efficiency vs. Load
(V
OUT
= 3.3V; L = 6.8µH)
100
80
2.0
AAT1147
DC Regulation
(V
OUT
= 3.3V)
1.5
V
IN
= 3.6V
Output Error (%)
Efficiency (%)
1.0
0.5
0.0
-0.5
-1.0
-1.5
60
V
IN
= 4.2V
V
IN
= 4.2V
40
20
0
1
10
100
1000
V
IN
= 5.0V
V
IN
= 3.6V
V
IN
= 5.0V
-2.0
0.1
1
10
100
1000
Output Current (mA)
Output Current (mA)
Efficiency vs. Load
(V
OUT
= 2.5V; L = 6.8µH)
100
80
2.0
1.5
DC Regulation
(V
OUT
= 2.5V)
Output Error (%)
Efficiency (%)
V
IN
= 3.6V
1.0
0.5
0.0
-0.5
-1.0
-1.5
60
40
20
0
V
IN
= 4.2V
V
IN
= 4.2V
V
IN
= 5.0V
V
IN
= 5.0V
V
IN
= 3.6V
1
10
100
1000
1
10
100
1000
-2.0
0.1
Output Current (mA)
Output Current (mA)
Efficiency vs. Load
(V
OUT
= 1.8V; L = 4.7µH)
100
80
2.0
1.5
DC Regulation
(V
OUT
= 1.8V)
Output Error (%)
V
IN
= 3.0V
V
IN
= 3.6V
Efficiency (%)
1.0
0.5
0.0
-0.5
-1.0
-1.5
60
40
20
0
1
10
100
1000
V
IN
= 4.2V
V
IN
= 4.2V
V
IN
= 3.6V
V
IN
= 3.0V
-2.0
0.1
1
10
100
1000
Output Current (mA)
Output Current (mA)
1147.2006.05.1.0
5