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Электронный компонент: AAT1265

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General Description
The AAT1265 is a member of Analogic Tech's Total
Power Management ICTM (TPMICTM) product family
and is designed for single-cell or dual-cell alkaline,
NiMH, or NiCd battery-powered applications. It is a
high efficiency, synchronous, fixed frequency, step-
up converter with true output disconnect during
shutdown (<1.0A), start-up inrush current limit, and
short-circuit protection.
The high 2MHz switching frequency and completely
integrated control circuitry minimize the total solution
footprint area while maintaining excellent regulation,
ripple, and transient response throughout the full
load range.
Light load switching frequency modulation and low
quiescent current maintain high efficiency perform-
ance for light load and sleep mode conditions.
With a 1A peak switch current limit, the AAT1265 is
capable of delivering 100mA to a 3.3V load with a
single AA cell or up to 250mA from a dual AA cell.
The device has a 1.0V start-up voltage with opera-
tion down to 0.8V.
The AAT1265 is available in a Pb-free, space-sav-
ing 2.0x2.1mm 8-pin SC70JW package and is
rated over the -40C to +85C temperature range.
Features
100mA Output from a Single AA Cell Input
250mA Output from a Dual AA Cell Input
V
IN
Operation Range: 0.8V to V
OUT
Up to 93% Efficiency
Low Start-Up Voltage: 1.0V Typical
Internal Synchronous Rectifier
Current Mode Control with Internal Feedback
and Compensation
2MHz Fixed Switching Frequency
1A Current Limit
Maintains High Efficiency Over the Output
Current Range for Improved Battery Life
Low 40A No Load Bias Current
True Load Disconnect
Short-Circuit and Over-Current Protection
Inrush Current Limit and Soft Start
Low Shutdown Current: <1.0A
-40C to +85C Temperature Range
2.0x2.1mm SC70JW-8 Package
Applications
BluetoothTM Headsets
Digital Cameras
Medical Instruments
Mobile Handsets
MP3 and Portable Music Players
AAT1265
Low Voltage 2MHz Step-Up DC/DC
Converter in SC70JW Package
Typical Application
Dual-Cell to 3.3V Efficiency
vs. Output Current
Output Current (mA)
Efficiency (%)
50
60
70
80
90
100
0.1
1.0
10.0
100.0
1000.0
V
IN
= 3.0V
V
IN
= 2.4V
V
IN
= 2.0V
2.2H
4.7F
4.7F
V
IN
V
OUT
VCC
EN
VIN
LX
OUT
GND
AAT1265
1265.2006.05.1.1
1
SwitchReg
TM
Pin Descriptions
Pin Configuration
SC70JW-8
(Top View)
EN
VIN
LX
GND
GND
GND
OUT
VCC
1
2
3
4
5
6
7
8
Pin #
Symbol
Function
1
VCC
Bias supply voltage after start-up and feedback to the output voltage error amplifier.
2
EN
Enable pin. Logic high enables the IC. Logic low disables the IC and disconnects the
load from the input. Shutdown current is <1A.
3
VIN
Battery input voltage. Supplies the IC at start-up.
4
LX
Inductor connection. Ties to the drains of the P-channel synchronous rectifier and the
N-channel MOSFET switch.
5
OUT
Boost converter output voltage; connects to the P-channel synchronous MOSFET
source. Bypass with ceramic capacitor to GND.
6, 7, 8
GND
Signal and power ground. Connect output capacitor return.
AAT1265
Low Voltage 2MHz Step-Up DC/DC
Converter in SC70JW Package
2
1265.2006.05.1.1
Absolute Maximum Ratings
Thermal Characteristics
1
Symbol
Description
Value
Units
JA
Maximum Thermal Resistance
160
C/W
P
D
Maximum Power Dissipation
625
mW
Symbol
Description
Value
Units
V
N
VIN, OUT, VCC, EN, LX to GND
-0.3 to 6.0
V
T
J
Operating Junction Temperature Range
-40 to 150
C
T
LEAD
Maximum Soldering Temperature (at leads, 10 sec)
300
C
AAT1265
Low Voltage 2MHz Step-Up DC/DC
Converter in SC70JW Package
1265.2006.05.1.1
3
1. Mounted on an FR4 board.
Electrical Characteristics
1
V
IN
= 1.2V, V
OUT
= 3.3V, T
A
= -40C to +85C, unless otherwise noted. Typical values are T
A
= 25C.
Symbol
Description
Conditions
Min
Typ
Max
Units
V
IN
Minimum Start-Up Voltage
I
LOAD
= 1mA
1.0
V
Operating Input Voltage Range
0.8
V
OUT
V
OUT
Output Voltage Accuracy
V
IN
= 0.8V to 2.5V,
3.2
3.3
3.4
V
PWM Mode
I
Q
Quiescent Supply Current
No Load
40
70
A
(PFM Operation)
2
I
SHDN
Shutdown Current
EN = 0V, V
IN
= 5.5V
1.0
A
R
DS(ON)H
PMOS On-Resistance
T
A
= 25C
750
m
R
DS(ON)L
NMOS On-Resistance
T
A
= 25C
400
m
I
LIMIT
NMOS Current Limit
1.0
A
I
PFM
PFM Light Load Current Threshold
20
mA
Efficiency
I
OUT
= 50mA, L = 2.2H
82
%
V
OUT
/V
OUT
Load Regulation
I
LOAD
= 0 to 100mA
1.5
%
V
OUT
(V
OUT
*
V
IN
)
Line Regulation
V
IN
= 0.8V to 2.5V
0.2
%/V
F
OSC
Switching Frequency
T
A
= 25C
1.8
2.0
2.2
MHz
D
TYMAX
Maximum Duty Cycle
90
%
V
TH(L-IN)
Logic Input Low Threshold for EN
0.4
V
V
TH(H-IN)
Logic Input High Threshold for EN
1.0
V
AAT1265
Low Voltage 2MHz Step-Up DC/DC
Converter in SC70JW Package
4
1265.2006.05.1.1
1. The AAT1265 is guaranteed to meet performance specifications over the -40C to +85C operating temperature range and is assured
by design, characterization, and correlation with statistical process controls.
2. I
Q
= I
Q_VOUT
= I
Q_VCC
.
Typical Characteristics
PFM Mode Output Current Threshold
vs. Input Voltage
Input Voltage (V)
Output Current (mA)
0
20
40
60
80
100
120
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
3.0
Increasing Load
Decreasing Load
Minimum Start-Up Voltage vs. Load Current
Current (mA)
Voltage (V)
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
0
2
40
60
80
100
120
140
160
Resistive Load
Constant Current Load
Dual-Cell Load Regulation
(V
O
= 3.3V)
Output Current (mA)
V
OUT
Error (%)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
0.1
1
10
100
1000
V
IN
= 2.0V
V
IN
= 2.4V
V
IN
= 3.0V
Single-Cell Load Regulation
(V
O
= 3.3V)
Output Current (mA)
V
OUT
Error (%)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
0.1
1
10
100
V
IN
= 1.5V
V
IN
= 1.2V
Dual-Cell to 3.3V Efficiency
Output Current (mA)
Efficiency (%)
50
60
70
80
90
100
0.1
1
10
100
1000
V
IN
= 3.0V
V
IN
= 2.4V
V
IN
= 2.0V
Single-Cell to 3.3V Efficiency
Output Current (mA)
Efficiency (%)
50
60
70
80
90
100
0.1
1
10
100
1000
V
IN
= 1.2V
V
IN
= 1.5V
AAT1265
Low Voltage 2MHz Step-Up DC/DC
Converter in SC70JW Package
1265.2006.05.1.1
5