AAT1156
1MHz 700mA Step-Down DC-DC Converter
General Description
The AAT1156 SwitchReg™ is a member of
AnalogicTech™'s Total Power Management IC™
(TPMIC™) product family. The step-down switching
converter is ideal for applications where high effi-
ciency is required over the full range of load condi-
tions. The 2.7V to 5.5V input voltage range makes
the AAT1156 ideal for single-cell lithium-ion/polymer
battery applications. Capable of more than 700mA
with internal MOSFETs, the current-mode con-
trolled IC provides high efficiency over a wide oper-
ating range. Fully integrated compensation simpli-
fies system design and lowers external parts count.
The AAT1156 is available in the 16-pin 3x3mm
QFN package and is rated over the -40°C to +85°C
temperature range.
Features
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SwitchReg
™
V
IN
Range: 2.7 to 5.5 Volts
Up to 95% Efficiency
110mΩ R
DS(ON)
Internal Switches
<1µA Shutdown Current
1MHz Step-Down Switching Frequency
Fixed or Adjustable V
OUT
≥
0.8V
Integrated Power Switches
Current Mode Operation
Internal Compensation
Stable with Ceramic Capacitors
Internal Soft Start
Over-Temperature Protection
Current Limit Protection
16-Pin QFN 3x3mm Package
-40°C to +85°C Temperature Range
Applications
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Cellular Phones
Digital Cameras
MP3 Players
Notebook Computers
PDAs
Wireless Notebook Adapters
Typical Application
U1
AAT1156
12
R1
100
C1
10µF
11
10
7
9
6
C2
0.1
µF
8
5
VP
VP
VP
EN
VCC
LL
NC
SGND
FB
LX
LX
LX
NC
PGND
PGND
PGND
4
15
14
13
16
3
2
1
R4
59k
C3, C4
2 x 22µF
L1
4.7µH
R3
187k
INPUT
2.5V
(V
OUT
= 2.5V; L = 4.7µH; CDRH3D16)
µ
100
95
AAT1156 Efficiency
V
IN
= 3.0V
V
IN
= 4.2V
V
IN
= 3.6V
Efficiency (%)
90
85
80
75
70
65
60
55
50
1
10
100
1000
C1 Murata 10µF 6.3V X5R GRM42-6X5R106K6.3
C3-C4 MuRata 22µF 6.3V GRM21BR60J226ME39L X5R 0805
L1 Sumida CDRH3D16-4R7NC
Output Current (mA)
1156.2005.11.1.2
1
ANALOGICTECH [ ADVANCED ANALOGIC TECHNOLOGIES ]
