PRODUCT DATASHEET
AAT1157
SwitchReg
TM
Electrical Characteristics
1
V
IN
= V
CC
= V
P
= 5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= 25°C.
Symbol
V
IN
V
OUT
ΔV
OUT
/V
OUT
ΔV
OUT
(V
OUT
*ΔV
IN
)
I
Q
I
SHDN
I
LIM
V
UVLO
V
UVLO(HYS)
V
IL
V
IH
I
IL
I
IH
R
DS(ON)H
R
DS(ON)L
F
OSC
T
SD
T
HYS
1MHz 1.2A Buck DC/DC Converter
Description
Input Voltage Range
Output Voltage Tolerance
Load Regulation
Line Regulation
Quiescent Supply Current
Shutdown Current
Current Limit
Under-Voltage Lockout
Under-Voltage Lockout Hysteresis
Input Low Voltage
Input High Voltage
Input Low Current
Input High Current
High Side Switch On Resistance
Low Side Switch On Resistance
Oscillator Frequency
Over-Temperature Shutdown Threshold
Over-Temperature Shutdown Hysteresis
Conditions
V
IN
= V
OUT
+ 0.2 to 5.5V, I
OUT
= 0 to 1.2A
V
IN
= 4.2V, I
LOAD
= 0 to 1.2A
V
IN
=2.7 to 5.5V
No Load
V
EN
= 0V, V
IN
= 5.5V
T
A
= 25°C
V
IN
Rising, V
EN
= V
CC
V
IN
Falling, V
EN
= V
CC
Min
2.7
-4
Typ
Max
5.5
+4
Units
V
%
%
%/V
±2.5
±0.1
160
1.7
2.5
1.2
250
0.6
1.4
300
1.0
μA
μA
A
V
mV
V
V
μA
μA
mΩ
mΩ
kHz
°C
°C
V
IN
= V
FB
= 5.5V
V
IN
= V
FB
= 0V
T
A
= 25°C
T
A
= 25°C
T
A
= 25°C, Adjustable Version
T
A
= 25°C, 3.3V Version
750
600
110
100
1000
850
140
15
1.0
1.0
150
150
1250
1200
1. The AAT1157 is guaranteed to meet performance specifications over the -40°C to +85°C operating temperature range and is assured by design, characterization, and correla-
tion with statistical process controls.
4
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