Uses Low Equivalent Series Resistance (ESR) Ceramic
Capacitors
Noise Reduction Bypass Capacitor
Shutdown Mode for Longer Battery Life
Low Temperature Coefficient
Factory-Programmed Output Voltages
SOT23 6-Pin or SC70JW 8-Pin Package
General Description
The AAT3238 MicroPower low dropout (LDO) linear regu-
lator is ideally suited for portable applications where
very fast transient response, extended battery life, and
small size are critical. The AAT3238 has been specifically
designed for high-speed turn-on and turn-off perfor-
mance, fast transient response, good power supply rip-
ple rejection (PSRR), and is reasonably low noise, mak-
ing it ideal for powering sensitive circuits with fast
switching requirements.
Other features include low quiescent current, typically
70µA, and low dropout voltage, typically less than
400mV at the maximum output current level of 300mA.
The device is output short-circuit protected and has a
thermal shutdown circuit for additional protection under
extreme operating conditions.
The AAT3238 also features a low-power shutdown mode
for extended battery life. A reference bypass pin has
been provided to improve PSRR performance and output
noise by connecting a small external capacitor from the
AAT3238’s reference output to ground.
The AAT3238 is available in a Pb-free, space-saving
6-pin SOT23 or 8-pin SC70JW package in factory-pro-
grammed voltages.
Applications
•
•
•
•
•
Cellular Phones
Digital Cameras
Notebook Computers
Personal Portable Electronics
Portable Communication Devices
Typical Application
V
IN
IN
OUT
V
OUT
AAT3238
ON/OFF
EN
GND
1µF
10nF
2.2µF
BYP
GND
GND
3238.2008.05.1.7
www.analogictech.com
1
PRODUCT DATASHEET
AAT3238
PowerLinear
TM
300mA MicroPower
TM
High Performance LDO Linear Regulator
Pin Descriptions
Pin #
SOT23-6
1
2, 5
3
4
6
SC70JW-8
5, 6
8
7
1
2, 3, 4
Symbol
IN
GND
EN
BYP
OUT
Function
Input voltage pin; should be decoupled with 1µF or greater capacitor.
Ground connection pin.
Enable pin; this pin should not be left floating. When pulled low, the PMOS pass transistor
turns off and all internal circuitry enters low-power mode, consuming less than 1µA.
Bypass capacitor connection; to improve AC ripple rejection, connect a 10nF capacitor to
GND. This will also provide a soft-start function.
Output pin; should be decoupled with 2.2µF ceramic capacitor.
Pin Configuration
SOT23-6
(Top View)
SC70JW-8
(Top View)
IN
GND
EN
1
6
OUT
GND
BYP
BYP
OUT
OUT
OUT
1
2
3
4
8
7
6
5
2
5
3
4
GND
EN
IN
IN
2
www.analogictech.com
3238.2008.05.1.7
PRODUCT DATASHEET
AAT3238
PowerLinear
TM
300mA MicroPower
TM
High Performance LDO Linear Regulator
Absolute Maximum Ratings
1
T
A
= 25°C, unless otherwise noted.
Symbol
V
IN
V
ENIN(MAX)
I
OUT
T
J
Description
Input Voltage
Maximum EN to Input Voltage
DC Output Current
Operating Junction Temperature Range
Value
6
0.3
P
D
/(V
IN
- V
O
)
-40 to 150
Units
V
V
mA
°C
Recommended Operating Conditions
Symbol
V
IN
T
Description
Input Voltage
Ambient Temperature Range
2
Rating
(V
OUT
+ V
DO
) to 5.5
-40 to +85
Units
V
°C
Thermal Information
3
Symbol
Θ
JA
P
D
Description
Maximum Thermal Resistance
Maximum Power Dissipation
Rating
150
667
Units
°C/W
mW
1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at conditions other than the operating conditions
specified is not implied. Only one Absolute Maximum Rating should be applied at any one time.
2. Mounted on a demo board.
3. To calculate minimum input voltage, use the following equation: V
IN(MIN)
= V
OUT(MAX)
+ V
DO(MAX)
as long as V
IN
≥
2.5V.
3238.2008.05.1.7
www.analogictech.com
3
PRODUCT DATASHEET
AAT3238
PowerLinear
TM
300mA MicroPower
TM
High Performance LDO Linear Regulator
Electrical Characteristics
1
V
IN
= V
OUT(NOM)
+ 1V for V
OUT
options greater than 1.5V. V
IN
= 2.5V for V
OUT
≤
1.5V. I
OUT
= 1mA, C
OUT
= 2.2µF, C
IN
= 1µF,
T
A
= -40°C to +85°C, unless otherwise noted. Typical values are T
A
= 25°C.
Symbol
V
OUT
I
OUT
V
DO
I
SC
I
Q
I
SD
∆V
OUT
/
V
OUT
*∆V
IN
∆V
OUT
(line)
∆V
OUT
(load)
t
ENDLY
V
EN(L)
V
EN(H)
I
EN
PSRR
T
SD
T
HYS
e
N
TC
Description
Output Voltage Tolerance
Output Current
Dropout Voltage
2, 3
Short-Circuit Current
Ground Current
Shutdown Current
Line Regulation
Dynamic Line Regulation
Dynamic Load Regulation
Enable Delay Time
Enable Threshold Low
Enable Threshold High
Leakage Current on Enable Pin
Power Supply Rejection Ratio
Over-Temperature Shutdown Threshold
Over-Temperature Shutdown Hysteresis
Output Noise
Output Voltage Temperature Coefficient
Conditions
I
OUT
= 1mA to 300mA
T
A
= 25°C
T
A
= -40 to 85°C
Min
-1.5
-2.5
300
Typ
Max
1.5
2.5
Units
%
mA
mV
mA
µA
%/V
mV
mV
µs
V
V
µA
dB
°C
°C
µVrms
ppm/°C
V
OUT
> 1.2V
I
OUT
= 300mA
V
OUT
< 0.4V
V
IN
= 5V, No Load, EN = V
IN
V
IN
= 5V, EN = 0V
V
IN
= V
OUT
+ 1 to 5.0V
V
IN
= V
OUT
+ 1V to V
OUT
+ 2V, I
OUT
= 300mA,
T
R
/T
F
= 2µs
I
OUT
= 1mA to 300mA, T
R
< 5µs
BYP = Open
70
400
600
125
600
µA
1
0.09
2.5
60
15
0.6
1.5
V
EN
= 5V
I
OUT
= 10mA, C
BYP
= 10nF
1kHz
10kHz
1MHz
67
47
45
145
12
50
22
1
1. The AAT3238 is guaranteed to meet performance specifications over the -40°C to +85°C operating temperature range and is assured by design, characterization, and correla-
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