PRODUCT DATASHEET
AAT1217
SwitchReg
TM
General Description
The AAT1217 is a high efficiency, synchronous, fixed
frequency, step-up converter designed for single-cell or
dual-cell alkaline, NiMH, or NiCd battery-powered appli-
cations. The high 1.2MHz switching frequency and com-
pletely integrated control circuitry minimize the total
solution footprint area while maintaining excellent regu-
lation, ripple, and transient response throughout the full
load range.
Light load mode operation and low quiescent current
allow the AAT1217 to maintain high efficiency perfor-
mance for light load conditions. With a 1.2A peak induc-
tor current limit, the AAT1217 is capable of delivering
100mA to the load from a single AA cell, 400mA from
dual AA cells, or up to 500mA from a single-cell lithium-
ion battery. The AAT1217 has a 0.85V start-up voltage
with operation down to 0.5V.
The AAT1217 is available in a Pb-free, space-saving low
profile (1mm) 6-pin TSOT23 or 6-pin SOT23 package
and is rated over the -40°C to +85°C ambient tempera-
ture range.
600mA, 1.2MHz, Micropower Synchronous Step-Up Converter
Features
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
V
IN
Operation Range: 0.5V to V
OUT
V
OUT
Range: 2.5V to 5.5V
100mA Output from a Single AA Cell Input
400mA Output from a Dual AA Cell Input
500mA Output from a Single Li+ Cell Input
High Efficiency: Up to 93% Efficiency
Low Start-Up Voltage: 0.85V Typical
Internal Synchronous Rectifier
▪
V
OUT
≤
4.5V: No External Schottky Diode
Fixed Frequency Pulse Width Modulation (PWM) Current-
Mode Control Scheme with Internal Compensation
1.2MHz Fixed Switching Frequency
1.2A Current Limit
Light Load Mode Operation
Over-Current Protection
EMI Reduction Anti-Ringing Control Circuitry
Low Shutdown Current: <1.0μA
-40°C to +85°C Ambient Temperature Range
Low Profile (1mm) TSOT23-6 or SOT23-6 Package
Applications
•
•
•
•
•
•
Cellular and Smart Phones
Digital Still and Video Cameras
Microprocessors and DSP Core Supplies
MP3 Player
Portable Instruments
Wireless and DSL Modems
Typical Application
L1
4.7μH
L1
4.7μH
V
IN
0.85V
VIN
R3
1MΩ
SW
VOUT
V
OUT
3.3V,100 mA
C
OUT
4.7μF
V
IN
0.85V
SW
VIN
VOUT
V
OUT
3.3V, 100 mA
C
IN
4.7μF
AAT1217-1.2
SHDN
GND
FB
R1
1.02M
R2
604k
C
IN
4.7μF
R3
1MΩ
AAT1217-3.3
SHDN
GND
FB
C
OUT
4.7μF
1217.2008.03.1.3
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1
PRODUCT DATASHEET
AAT1217
SwitchReg
TM
Pin Descriptions
Pin #
1
2
3
4
5
6
600mA, 1.2MHz, Micropower Synchronous Step-Up Converter
Symbol
SW
GND
FB
SHDN
VOUT
VIN
Function
Power Switch Pin. Ties to the drains of the PMOS synchronous rectifier and the NMOS switch.
Ground Pin
Feedback Input Pin. Connect FB to the center point of the external resistor divider. The feedback threshold
voltage is 1.23V.
Shutdown Signal Input. Logic high enables the IC. Logic low disables the IC. Shutdown current is <1μA.
Power Output Pin. Tied to the source of the PMOS synchronous rectifier.
Power Supply Input. Must be closely decoupled to GND, Pin 2, with a 4.7μF or greater ceramic capacitor.
Pin Configuration
TSOT23-6/SOT23-6
(Top View)
SW
1
6
VIN
VOUT
SHDN
GND
FB
2
5
3
4
2
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1217.2008.03.1.3
PRODUCT DATASHEET
AAT1217
SwitchReg
TM
600mA, 1.2MHz, Micropower Synchronous Step-Up Converter
Absolute Maximum Ratings
1
Symbol
V
IN
V
SW
V
FB
, V
SHDN
V
OUT
T
A
T
STORAGE
T
LEAD
T
J
Description
Input Supply Voltage
SW Voltage
FB, SHDN Voltages
VOUT Voltage
Operating Ambient Temperature Range
2
Storage Temperature Range
Lead Temperature (Soldering, 10s)
Operating Junction Temperature Range
2
Value
-0.3 to 6
-0.3 to 6
-0.3 to 6
-0.3 to 6
-40 to 85
-65 to 150
300
-40 to 150
Units
V
V
V
V
°C
°C
°C
°C
Thermal Information
3
Symbol
θ
JA
P
D
Description
Maximum Thermal Resistance
Maximum Power Dissipation
TSOT23-6
SOT23-6
TSOT23-6
SOT23-6
Value
190
150
526
667
Units
°C/W
mW
1. Absolute Maximum Ratings are those values beyond which the life of a device may be impaired.
2. T
J
is calculated from the ambient temperature T
A
and power dissipation P
D
according to the following formula: T
J
= T
A
+ P
D
x
θ
JA
.
3. Mounted on an FR4 board.
1217.2008.03.1.3
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3
PRODUCT DATASHEET
AAT1217
SwitchReg
TM
600mA, 1.2MHz, Micropower Synchronous Step-Up Converter
Electrical Characteristics
1
V
IN
= 1.2V, V
OUT
= 3.3V, T
A
= 25°C, unless otherwise noted.
Symbol
V
IN
V
OUT
V
FB
ΔV
OUT
/
V
OUT
/ΔV
IN
Description
Minimum Start-Up Voltage
Minimum Operating Voltage
Output Voltage Range
Output Voltage Accuracy
3
Reference Voltage
Reference Voltage Line
Regulation
Conditions
I
OUT
= 1mA
V
SHDN
= V
IN
Min
Typ
0.85
0.5
Max
1
0.65
5.5
+4
Units
V
V
%
V
%/V
2.5
I
OUT
= 10mA; T
A
= -40°C to
+85°C
T
A
= -40°C to +85°C
V
IN
= 1.2V to 2.4V, I
OUT
= 10mA,
V
OUT
= 3.3V
V
IN
= 2.4V to 4.2V, I
OUT
=
10mA,V
OUT
= 5.0V
V
IN
= 1.2V, I
OUT
= 10mA to
100mA, V
OUT
= 3.3V
V
IN
= 3.6V, I
OUT
= 10mA to
400mA, V
OUT
= 5.0V
V
SHDN
= 0
Measured on V
OUT
, V
SHDN
= V
IN
V
SW
= 5V
V
SW
= 0V
V
OUT
= 3.3V
V
OUT
= 5V
V
OUT
= 3.3V
V
OUT
= 5V
-4
1.192
1.230
0.2
0.4
0.003
1.268
ΔV
OUT
/
V
OUT
/ΔI
OUT
I
Q
I
LNMOS
I
LPMOS
R
DS(ON)L
R
DS(ON)H
I
CL
Δt(I
CL
)
D
MAX
F
OSC
V
SHDN
I
SHDN
T
SD
Reference Voltage Load
Regulation
Quiescent Current (Shutdown)
Quiescent Current (Active)
NMOS Switch Leakage
PMOS Switch Leakage
NMOS Switch ON Resistance
PMOS Switch ON Resistance
NMOS Current Limit
Current Limit Delay to Output
Maximum Duty Cycle
Switching Frequency
SHDN Input Low
SHDN Input High
SHDN Input Current
Thermal Shutdown
%/mA
0.004
0.01
300
0.1
0.1
0.35
0.30
0.60
0.55
1200
40
85
1.2
1.5
0.35
1
1
500
5
5
μA
μA
μA
Ω
Ω
mA
ns
%
MHz
V
μA
°C
750
V
FB
= 1.15V, T
A
= -40°C to +85°C
T
A
= -40°C to +85°C
80
0.9
1.00
V
SHDN
= 5.5V
Hysteresis
0.01
160
20
1. Specifications over the temperature range are guaranteed by design, characterization, and correlation with statistical process controls.
2. Not including the current into internal resistance divider.
3. For fixed 3.3V and 5.0V output voltage version. The adjustable output voltage is guaranteed by reference voltage accuracy.
4
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1217.2008.03.1.3
PRODUCT DATASHEET
AAT1217
SwitchReg
TM
600mA, 1.2MHz, Micropower Synchronous Step-Up Converter
Typical Characteristics
Efficiency vs. Output Current
(V
OUT
= 3.3V; T
A
= 25°C)
°
100
90
80
100
Efficiency vs. Output Current
(V
OUT
= 5V; T
A
= 25°C)
°
V
IN
= 2.4V
V
IN
= 1.2V
V
IN
= 1.5V
V
IN
= 2.4V
Efficiency (%)
V
IN
= 1.5V
V
IN
= 1.2V
90
80
70
60
50
40
30
20
10
0
0.1
Efficiency (%)
V
IN
= 3.6V
70
60
50
40
30
20
10
0
0.1
1
10
100
1000
1
10
100
1000
Output Current (mA)
Output Current (mA)
Output Voltage vs. Output Current
(V
OUT
= 3.3V; T
A
= 25°C)
°
3.5
5.2
Output Voltage vs. Output Current
(V
OUT
= 5V; T
A
= 25°C)
°
Output Voltage (V)
3.4
Output Voltage (V)
5.1
V
IN
= 1.2V
3.3
V
IN
= 1.5V
V
IN
= 2.4V
V
IN
= 1.2V
V
IN
= 1.5V
V
IN
= 2.4V
V
IN
= 3.6V
5
3.2
4.9
3.1
0
100
200
300
400
500
600
4.8
0
100
200
300
400
500
600
Output Current (mA)
Output Current (mA)
Minimum Start-Up Voltage vs. Output Current
(V
OUT
= 3.3V; T
A
= 25°C)
°
1.5
Maximum Output Current vs. Input Voltage
(L = 4.7µH; T
A
= 25°C)
°
1000
Start-Up Voltage (V)
Maximum Output
Current (mA)
1.35
1.2
1.05
0.9
0.75
0.6
0
20
40
60
80
100
120
140
160
180
200
800
600
400
200
0
0.5
V
OUT
= 3.3V
V
OUT
= 5V
1
1.5
2
2.5
3
3.5
4
4.5
Output Current (mA)
Input Voltage (V)
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