AAT1157
1MHz 1.2A Buck DC/DC Converter
Typical Characteristics
Soft Start
(V
OUT
= 2.5V; I
OUT
= 1.2A; V
IN
= 3.6V)
Output Voltage (AC coupled)
(top) (V)
Enable and Output Voltage
(top) (V)
6.0
4.0
2.0
0.0
-2.0
-4.0
-6.0
-8.0
-10.0
3.5
3.0
0.02
0.01
0
-0.01
-0.02
-0.03
-0.04
-0.05
-0.06
0.5
0
2
1.5
1
Output Ripple
(V
OUT
= 2.5V; I
OUT
= 1.2A; V
IN
= 3.6V)
3
2.5
Inductor Current
(bottom) (A)
Inductor Current
(bottom) (A)
2.5
2.0
1.5
1.0
0.5
0.0
-0.5
Time (250µs/div)
µ
Time (500ns/div)
Line Transient
(I
OUT
= 1.2A; V
O
= 2.5V)
Output Voltage (AC Coupled)
(V) (top)
Output Voltage (AC coupled)
(bottom) (V)
4.4
4.2
0.24
0.20
0.16
0.12
0.08
0.04
0.00
-0.04
-0.08
0.08
0.05
0.02
-0.01
-0.04
-0.07
-0.10
-0.13
-0.16
Load Transient Response
(400mA-1.2A; V
IN
= 3.3V; V
OUT
= 2.5V)
4.0
3.5
3.0
2.5
2.0
Input Voltage
(top) (V)
4.0
3.8
3.6
3.4
3.2
3.0
2.8
Load Current
(A) (bottom)
1.2A
400mA
Time (20µs/div)
µ
1.5
1.0
0.5
0.0
Time (25µs/div)
µ
6
1157.2005.11.1.4
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
