AAT3258
300mA LDO Linear Regulator with P Reset
3258.2005.04.1.5
1
PowerLinear
TM
General Description
The AAT3258 combines a high performance, low
noise, 300mA low dropout (LDO) linear regulator
with a microprocessor reset monitor. The 300mA
output capability of the LDO regulator makes this
device ideal for use with microprocessors and DSP
cores in portable products. The microprocessor
reset monitor section has very low quiescent cur-
rent consumption and has an active low reset out-
put. The AAT3258 has separate input pins for the
reset monitor and LDO regulator so they may be
operated from independent sources for increased
design flexibility. This device features very low qui-
escent current, typically less than 71A.
The LDO regulator has low dropout voltage, typical-
ly 400mV at the full output current level, making it
ideal for portable applications where extended bat-
tery life is critical. The AAT3258 LDO regulator sec-
tion has complete over-current/short-circuit and
over-temperature protection circuits to guard against
extreme operating conditions. The device also has
an active output pull down function when disabled.
The AAT3258 is available in a space-saving 8-pin
TSOPJW package. This device is capable of oper-
ation over a -40C to +85C temperature range.
Features
Integrated LDO Regulator with P Reset
300mA Output LDO Regulator
Low Dropout Regulator, 400mV at 300mA
High LDO Output Voltage Accuracy, Typically
1.5%
Very Low Noise and High Power Supply
Rejection Ratio (PSRR) LDO
Low Quiescent Current at 71A
LDO Over-Current/Short-Circuit Protection
LDO Over-Temperature Protection
LDO Power Saving Shutdown Mode
Independent Device Power Inputs
High Accuracy Reset Monitor Threshold: 1.5%
Active Low Push-Pull Monitor Reset Output
<2.0A of Shutdown Current
Uses Low Equivalent Series Resistance
(ESR) Ceramic Capacitors
-40C to +85C Temperature Range
8-Pin TSOPJW Package
Applications
Cellular Phones
Digital Cameras
Handheld Instrumentation
Microprocessor/DSP Core/IO Power
Notebook Computers
PDAs and Handheld Computers
Portable Communication Devices
Typical Application
AAT3258
1
F
2.2
F
100k
10nF
LDO Shutdown
P Reset
Manual Reset
VIN
RESET OUT
LDO VOUT
VOUT
RESET
GND
SHDN
BYP
MR
VDET
VIN
AAT3258
300mA LDO Linear Regulator with P Reset
2
3258.2005.04.1.5
Pin Descriptions
Pin Configuration
TSOPJW-8
(Top View)
1
2
3
4
8
7
6
5
VIN
SHDN
VDET
MR
OUT
BYP
GND
RESET
Pin #
Symbol
Function
1
VIN
LDO voltage regulator input pin. This pin should be decoupled with 1F or
greater capacitor. See application information.
2
SHDN
LDO voltage regulator shutdown pin. This pin should not be left floating.
When connected low, all the internal circuitry is powered down. When high, it
is in normal operation.
3
VDET
Microprocessor reset input power supply pin. It may be connected to V
IN
.
4
MR
Manual reset active low input. A logic low signal on MR asserts a reset condi-
tion. Asserted reset continues as long as MR is low and for a minimum of
150ms after MR returns high.
5
RESET
Reset output remains low while V
DET
is below the reset threshold and remains
so for a minimum of 150ms after V
DET
rises above the reset threshold.
6
GND
Ground connection pin.
7
BYP
LDO voltage regulator bypass capacitor connection. To improve AC ripple
rejection and decrease LDO regulator self noise, connect a 10nF ceramic
capacitor between this pin and GND.
8
OUT
LDO voltage regulator output pin; should be decoupled with a 2.2F or
greater value low ESR ceramic capacitor.
Absolute Maximum Ratings
1
T
A
= 25C, unless otherwise noted.
Thermal Information
2
Recommended Operating Conditions
Symbol
Description
Value
Units
V
IN
Input Voltage to LDO
3
(V
OUT
+V
DO
) to 5.5
V
V
DET
Input Voltage to P Reset (0 to 70C)
1.0 to 5.5
V
T
Ambient Temperature Range
-40 to +85
C
Symbol
Description
Value
Units
JA
Maximum Thermal Resistance (TSOPJW-8)
150
C/W
P
D
Maximum Power Dissipation (TSOPJW-8)
833
mW
Symbol
Description
Value
Units
V
IN
Input Voltage
6.0
V
V
RESET
RESET to GND
-0.3 to V
DET
+0.3
V
V
SHDNIN(MAX)
Maximum SHDN to Input Voltage
0.3
V
I
OUT
LDO Regulator DC Output Current
P
D
/(V
IN
-V
O
)
mA
I
RESET
Maximum Reset Output Current
20
mA
V
DET
/
t
Maximum Rate of V
DET
Rise
100
V/s
T
J
Operating Junction Temperature Range
-40 to 150
C
AAT3258
300mA LDO Linear Regulator with P Reset
3258.2005.04.1.5
3
1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at condi-
tions 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.
AAT3258
300mA LDO Linear Regulator with P Reset
4
3258.2005.04.1.5
Electrical Characteristics
1
T
J
= 25C, unless otherwise noted.
Symbol
Description
Conditions
Min
Typ Max
Units
300mA LDO Regulator
V
OUT
Output Voltage
I
OUT
= 1mA
T
A
= 25C
-1.5
1.5
%
to 300mA
T
A
= -40C to 85C
-2.5
2.5
I
OUT
Output Current
V
OUT
> 1.2V
300
mA
I
SC
Short-Circuit Current
V
OUT
< 0.4V
600
mA
I
GND
Ground Current
V
IN
= 5V, No Load, SHDN = V
IN
70
125
A
I
SHDN
Shutdown Current
V
IN
= 5V, SHDN = 0V
1.0
A
V
OUT
/V
OUT
*
V
IN
Line Regulation
V
IN
= V
OUT
+ 1 to 5.0V
0.09
%/V
V
OUT
(line)
Dynamic Line Regulation
I
OUT
= 300mA, T
R
/T
R
= 2s,
2.5
mV
V
IN
= V
OUT
+ 1V to V
OUT
+ 2V
V
OUT
(load)
Dynamic Load Regulation
I
OUT
= 1mA to 300mA, T
R
< 5s
60
mV
T
ENDLY
Enable Delay Time
BYP = Open
15
s
V
DO
Dropout Voltage
2
I
OUT
= 300mA
400
600
mV
V
IL
Input Low Voltage
0.6
V
V
IH
Input High Voltage
1.5
V
I
IL
Input Low Current
1.0
A
I
IH
Input High Current
1.0
A
1kHz
67
PSRR
Power Supply Rejection Ratio
I
OUT
= 10mA, 10kHz
47
dB
C
BYP
= 10nF
1MHz
45
T
SD
Over-Temperature Shutdown
145
C
Threshold
T
HYS
Over-Temperature Shutdown
12
C
Hysteresis
e
N
Output Noise
50
V
RMS
TC
Output Voltage Temperature
22
ppm/C
Coefficient
1. The AAT3258 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. V
DO
is defined as V
IN
- V
OUT
when V
OUT
is 98% of nominal.
AAT3258
300mA LDO Linear Regulator with P Reset
3258.2005.04.1.5
5
Electrical Characteristics
1
T
A
= 25C, unless otherwise noted.
Symbol
Description
Conditions
Min
Typ
Max
Units
Microprocessor Reset Monitor
V
DET
Input Voltage Range
T
A
= 0C to +70C
1
5.5
V
T
A
= -40C to +85C
1.2
5.5
I
Q
Quiescent Current
V
CC
= 5.5V
1.05
3.0
A
V
CC
= 3.0V
0.85
2.0
I
DD
Operating Supply Current
V
DET
= 3.0V
0.85
2.0
A
I
DOFF
Reset Leakage Current
V
DET
> V
TH
1.0
A
V
TH
Reset Threshold Voltage
T
A
= 25C
AAT3258xxx-x.x-R
2.59
2.63
2.67
V
AAT3258xxx-x.x-Y
2.41
2.45
2.49
V
TH
/C
RESET Threshold Tempco
40
ppm/C
T
P
Reset Propagation Delay
V
DET
= V
TH
to (V
TH
- 100mV)
15
s
T
RDY
Reset Active Timeout Period
150
250
400
ms
T
MR
MR Minimum Pulse Width
10
s
MRGI
MR Glitch Immunity
100
ns
R
MR
MR Pull-Up Resistance
30
65
90
k
T
MD
MR to Reset Propagation
0.5
s
Delay
V
IH
MR Input Threshold (high)
V
DET
= V
TH(MAX)
0.7
V
DET
V
V
IL
MR Input Threshold (low)
V
DET
= V
TH(MAX)
0.25
V
DET
V
I
SINK
= 1.2mA, V
DET
= V
TH(MIN)
,
0.3
V
TH
3.08V, Reset Asserted
V
OL
Reset Low Voltage
I
SINK
= 3.2mA, V
DET
= V
TH(MIN)
,
0.4
V
V
TH
>
3.08V, Reset Asserted
I
SOURCE
= 800A, V
DET
> 3.08V,
V
DET
- 1.5
V
DET
> V
TH(MAX)
V
OH
Reset High Voltage
I
SOURCE
= 500A, V
DET
>
0.8 * V
DET
V
V
TH(MAX)
, V
TH
3.08V
1. The AAT3258 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.
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