Datasheet
AS1361/AS1362
150mA/300mA, Ultra-Low-Noise, High-PSRR
Low Dropout Regulators, with POK
1 General Description
The AS1361/AS1362 are ultra-low-noise, low-dropout
linear regulators specifically designed to deliver up to
150/300mA continuous output current, and can achieve
a low 140mV dropout for 300mA load current. The LDOs
are designed and optimized to work with low-cost, small-
capacitance ceramic capacitors.
The devices are available as the standard products
listed in
Table 1.
Table 1. Standard Products
Model
AS1361
AS1362
Load Current
150mA
300mA
Output Voltage
Preset – 1.5 to 4.5V
Preset – 1.5 to 4.5V
2 Key Features
!
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Preset Output Voltages: 1.5 to 4.5V (in 50mV steps)
Output Noise: 9µV
RMS
@ 100Hz to 100kHz
Power-Supply Rejection Ratio: 92dB @ 1kHz
Low Dropout: 140mV @ 300mA Load
Power-OK Output
Stable with 1µF Ceramic Capacitor for any Load
Guaranteed 150/300mA Output
1.25V Internal Reference
Extremely-Low Quiescent Current: 40µA
Excellent Load/Line Transient
Overcurrent and Thermal Protection
TSOT23 6-pin Package
An integrated P-channel MOSFET pass transistor allows
the devices to maintain extremely low quiescent current
(40µA).
The AS1361/AS1362 uses an advanced architecture to
achieve ultra-low output voltage noise of 9µV
RMS
and a
power-supply rejection-ratio of better than 80dB (up to
10kHz).
An active-Low, open-drain power-ok output indicates if
the output voltage is within regulation.
The AS1361/AS1362 requires only 1µF output capacitor
for stability at any load. When the LDO is disabled, cur-
rent consumption drops below 500nA.
The devices are available in a TSOT23 6-pin package.
3 Applications
The devices are ideal for mobile phones, wireless
phones, PDAs, handheld computers, mobile phone
base stations, Bluetooth portable radios and accesso-
ries, wireless LANs, digital cameras, personal audio
devices, and any other portable, battery-powered appli-
cation.
Figure 1. Typical Application Circuit
Input
2 to 5.5V
C
IN
1µF
1
IN
6
OUT
Output
1.5 to 4.5V
IN 1
100kΩ
6 OUT
On
Off
3
SHDNN
AS1361/
AS1362
4
POK
GND 2
AS1361/
AS1362
5 BYPASS
2
GND
5
BYPASS
C
BYPASS
10nF
C
OUT
1µF
SHDNN 3
4 POK
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AS1361/AS1362
Datasheet - P i n o u t
4 Pinout
Pin Assignments
Figure 2. Pin Assignments (Top View)
IN 1
6 OUT
GND 2
AS1361/
AS1362
5 BYPASS
SHDNN 3
4 POK
TSOT23 6-pin
Pin Descriptions
Table 2. Pin Descriptions
Pin Number
1
2
3
Pin Name
IN
GND
SHDNN
Unregulated Input Supply.
Ground
Shutdown.
Pull this pin low to disable the LDO.
Power-OK Output.
Active-Low, open-drain output indicates if the output
voltage is within regulation.
0 = V
OUT
<94% V
OUTNOM
1 = V
OUT
>94% V
OUTNOM
Noise Bypass for Low-Noise Operation.
Connect a 10nF capacitor from
this pin to
OUT.
Note:
This pin is shorted to GND in shutdown mode.
Regulated Output Voltage.
Bypass this pin with a capacitor to GND. See
Capacitor Selection and Regulator Stability on page 12
for more details.
Description
4
POK
5
BYPASS
6
OUT
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AS1361/AS1362
Datasheet - A b s o l u t e M a x i m u m R a t i n g s
5 Absolute Maximum Ratings
Stresses beyond those listed in
Table 3
may cause permanent damage to the device. These are stress ratings only,
and functional operation of the device at these or any other conditions beyond those indicated in
Electrical Character-
istics on page 4
is not implied. Exposure to absolute maximum rating conditions for extended periods may affect
device reliability.
Table 3. Absolute Maximum Ratings
Parameter
IN to GND
OUT, SHDNN, POK to GND
BYPASS to GND
Output Short-Circuit Duration
Thermal Resistance
Θ
JA
Operating Temperature Range
Junction Temperature
Storage Temperature Range
-65
-40
Min
-0.3
-0.3
-0.3
Max
+7
IN +
0.3
OUT +
0.3
Infinite
201.7
+85
+150
+150
ºC/W
ºC
ºC
ºC
The reflow peak soldering temperature (body
temperature) specified is in accordance with
IPC/JEDEC J-STD-020D “Moisture/Reflow
Sensitivity Classification for Non-Hermetic Solid
State Surface Mount Devices”.
The lead finish for Pb-free leaded packages is
matte tin (100% Sn).
on PCB
Units
V
V
V
Comments
Package Body Temperature
+260
ºC
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AS1361/AS1362
Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
6 Electrical Characteristics
V
IN
= V
OUT
+0.5V, C
IN
= 1µF, C
OUT
= 1µF, C
BYPASS
= 10nF, T
AMB
= -40 to +85ºC (unless otherwise specified). Typ val-
ues are at T
AMB
= +25ºC. Limits 100% tested at +25ºC. Limits over operating temperature range guaranteed by design.
Table 4. Electrical Characteristics
Symbol
V
IN
Parameter
Input Voltage Range
I
OUT
= 1mA, T
AMB
= +25ºC
I
OUT
= 100µA to 150mA, T
AMB
= +25ºC
(AS1361)
Output Voltage Accuracy
I
OUT
= 100µA to 300mA, T
AMB
= +25ºC
(AS1362)
I
OUT
= 100µA to 150mA, (AS1361)
I
OUT
= 100µA to 300mA, (AS1362)
I
OUT
I
LIMIT
Maximum Output Current
Current Limit
AS1361
AS1362
AS1361, OUT = 90% of nom., T
AMB
= +25ºC
AS1362, OUT = 90% of nom., T
AMB
= +25ºC
V
OUT
≥
3V, I
OUT
= 150mA
V
OUT
≥
3V, I
OUT
= 300mA, AS1362
Dropout Voltage
1
Condition
Min
2
-0.5
-0.75
-1.0
-1.5
-2.0
150
300
Typ
Max
5.5
+0.5
+0.75
+1.0
+1.5
+2.0
Unit
V
%
mA
270
510
70
140
90
170
140
270
40
150
0.02
0.0005
9
92
80
62
9
µV
dB
500
95
200
120
230
190
350
90
250
µA
%/V
%/mA
nA
mV
mA
2.5V
≤
V
OUT
<
3V, I
OUT
= 150mA
2.5V
≤
V
OUT
<
3V, I
OUT
= 300mA, AS1362
2.0V
≤
V
OUT
<
2.5V, I
OUT
= 150mA
2.0V
≤
V
OUT
<
2.5V, I
OUT
= 300mA, AS1362
I
OUT
= 0.05mA
V
IN
= V
OUTNOM
- 0.1V, I
OUT
= 0mA
V
IN
= (V
OUT
+0.5V) to 5.5V, I
OUT
= 0.1mA
I
OUT
= 1 to 150/300mA
SHDNN = 0V
f = 1kHz, I
OUT
= 10mA
f = 10kHz, I
OUT
= 10mA
f = 100kHz, I
OUT
= 10mA
f = 100Hz to 100kHz,
I
LOAD
= 0 to 150/300mA
I
Q
V
LNR
V
LDR
I
SHDNN
PSRR
Quiescent Current
Line Regulation
Load Regulation
Shutdown Supply Current
Ripple Rejection
Output Noise Voltage (RMS)
Shutdown
Shutdown Exit Delay
2
R
LOAD
= 50Ω
V
IN
= 2 to 5.5V
V
IN
= 2 to 5.5V
I
OUT
= 0, V
OUTRISING
Hysteresis, I
OUT
= 0
I
SINK
= 1mA
V
OUT
in regulation
1.5
90
94
1.5
300
0.4
µs
V
V
SHDNN Logic Low Level
SHDNN Logic High Level
Power-OK Output
V
POK
V
OL
Power-OK Voltage Threshold
POK Output Voltage Low
POK Output Leakage Current
98
0.3
1
%
V
OUT
V
µA
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AS1361/AS1362
Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
Table 4. Electrical Characteristics (Continued)
Symbol
Parameter
Thermal Shutdown
Temperature
Thermal Shutdown
Hysteresis
Condition
Min
Typ
Max
Unit
Thermal Protection
T
SHDNM
ΔT
SHDN
M
160
15
ºC
ºC
1. Dropout is defined as V
IN
- V
OUT
when V
OUT
is 100mV below the value of V
OUT
for V
IN
= V
OUT
+ 0.5V.
2. Time needed for V
OUT
to reach 90% of final value.
Note:
All limits are guaranteed. The parameters with min and max values are guaranteed with production tests or
SQC (Statistical Quality Control) methods.
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