AMSCO AS1374

Datasheet
AS1374
200mA, Ultra-Low-Noise, High-PSRR, Dual Low
Dropout Regulators
1 General Description
2 Key Features
The AS1374 is a ultra-low-noise, low-dropout linear regulator with two seperated outputs. Specifically designed
to deliver 200mA continuous output current at each output pin. The LDOs can achieve a low 120mV dropout for
200mA load current and are designed and optimized to
work with low-cost, small-capacitance ceramic capacitors.
An integrated P-channel MOSFET pass transistor allows
the devices to maintain extremely low quiescent current
(30µA).
The AS1374 uses an advanced architecture to achieve
ultra-low output voltage noise of 20µVRMS and a powersupply rejection-ratio of better than 85dB (@ 1kHz).
Two active-High enable pins allows to switch on or off
each output independently from each other.
The AS1374 requires only 1µF output capacitor for stability at any load.
!
Preset Output Voltages: 1.2 to 3.6V (in 50mV steps)
!
Output Noise: 20µVRMS @ 100Hz to 100kHz
!
Power-Supply Rejection Ratio: 85dB @ 1kHz
!
Low Dropout: 120mV @ 200mA Load
!
Stable with 1µF Ceramic Capacitor for any Load
!
Guaranteed 200mA Output
!
Pull-Down Option in Shutdown (factory set)
!
Extremely-Low Quiescent Current: 30µA
!
Excellent Load/Line Transient
!
Overcurrent and Thermal Protection
!
6-bump WLP Package
The device is available in a 6-bump WLP package.
3 Applications
The devices are ideal for mobile phones, wireless
phones, PDAs, handheld computers, mobile phone
base stations, Bluetooth portable radios and accessories, wireless LANs, digital cameras, personal audio
devices, and any other portable, battery-powered application.
Figure 1. AS1374 - Typical Application Circuit
Input
2V to 5.5V
2
Output1
1.2V to 3.6V
3
OUT 1
VDD
CIN
1µF
COUT1
1µF
6
EN 1
AS1374
Output2
1.2V to 3.6V
1
OUT 2
COUT2
1µF
4
EN 2
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5
GND
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AS1374
Datasheet - P i n o u t
4 Pinout
Pin Assignments
Figure 2. Pin Assignments (Top View)
1
2
3
AS1374
5
4
6
Pin Descriptions
Table 1. Pin Descriptions
Pin Number
Pin Name
Description
1
OUT 2
Regulated Output Voltage 2. Bypass this pin with a capacitor to GND. See
Capacitor Selection and Regulator Stability on page 11 for more details.
2
VDD
3
OUT 1
4
EN 2
Enable 2. Pull this pin to logic low to disable Regulated Output 2 voltage.
5
GND
Ground
6
EN 1
Enable 1. Pull this pin to logic low to disable Regulated Output 1 voltage.
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Input Supply
Regulated Output Voltage 1. Bypass this pin with a capacitor to GND. See
Capacitor Selection and Regulator Stability on page 11 for more details.
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AS1374
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 2 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 Characteristics on page 4 is not implied. Exposure to absolute maximum rating conditions for extended periods may affect
device reliability.
Table 2. Absolute Maximum Ratings
Parameter
Min
Max
Units
VDD to GND
-0.3
+7
V
OUT 1, OUT 2, EN 1, EN 2 to GND
-0.3
VDD +
0.3
V
Output Short-Circuit Duration
Infinite
ESD
2
Latch-Up
Thermal Resistance ΘJA
Operating Temperature Range
-40
Junction Temperature
Storage Temperature Range
Package Body Temperature
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Comments
-65
kV
HBM MIL-Std. 883E 3015.7 methods
100
mA
@85°C, JEDEC 78
201.7
ºC/W
on PCB
+85
ºC
+150
ºC
+150
ºC
+260
ºC
Revision 1.03
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).
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AS1374
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
VIN = VOUT + 0.5V, VOUT = 2.85V, CIN = COUT = 1µF, TAMB = -40°C to +85ºC (unless otherwise specified). Typ values
are at TAMB = +25ºC.
Table 3. Electrical Characteristics
Symbol
Parameter
VIN
Input Voltage Range
Condition
ΔVOUT
Output Voltage Accuracy
IOUT
Maximum Output Current
IGND
Ground Current
ILIMIT
Current Limit
Dropout Voltage
Max
Unit
2
5.5
V
IOUT = 1mA, TAMB = +25ºC
-1
+1
IOUT = 100µA to 200mA, TAMB = +25ºC
-1.5
+1.5
IOUT = 100µA to 200mA
-2.5
+2.5
each channel
200
Typ
%
mA
one channel on, IOUT = 50µA
25
50
µA
one channel on, IOUT = 200mA
30
55
µA
300
400
mA
2.5V ≤ VOUT < 3V, IOUT = 100mA
60
120
mV
90
OUT = short
1
Min
210
both channels on, IOUT = 0.05mA
30
IQ
Quiescent Current
both channels on, VIN = VOUTNOM - 0.1V,
IOUT = 0mA
50
VLNR
Line Regulation
VIN = (VOUT +0.5V) to 5.5V, IOUT = 1mA
0.02
µA
%/V
VLDR
Load Regulation
IOUT = 1 to 200mA
0.0005
ISHDN
Shutdown Current
OUT 1 and OUT 2 disable
0.01
f = 1kHz, IOUT = 10mA
85
Ripple Rejection
f = 10kHz, IOUT = 10mA
65
f = 100kHz, IOUT = 10mA
50
Output Noise Voltage (RMS)
f = 100Hz to 100kHz, ILOAD = 20mA
20
µV
0.01
µA
PSRR
%/mA
2
µA
dB
Enable
Enable Input Bias Current
Enable Exit Delay
2
both channels initially off
150
one channel initially off
200
Enable Logic Low Level
µs
0.4
Enable Logic High Level
1.4
V
V
Thermal Protection
TSHDN
Thermal Shutdown
Temperature
160
ºC
ΔTSHDN
Thermal Shutdown
Hysteresis
15
ºC
1. Dropout is defined as VIN - VOUT when VOUT is 100mV below the value of VOUT for VIN = VOUT + 0.5V.
2. Time needed for VOUT 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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AS1374
Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s
7 Typical Operating Characteristics
VIN = VOUT + 0.5V, VOUT = 2.85V, CIN = COUT = 1µF, TAMB = 25°C (unless otherwise specified).
Figure 4. Output Voltage vs. Input Voltage
2.88
2.88
2.87
2.87
Output Voltage (V)
Output Voltage (V)
Figure 3. Output Voltage vs. Temperature
2.86
2.85
2.84
2.86
2.85
2.84
Iload = 1mA
CH1
2.83
Iload = 10mA
2.83
Iload = 100mA
CH2
Iload = 200mA
2.82
-45 -30 -15
0
15
30
45
60
75
2.82
3.35
90
3.85
Temperature (°C)
4.35
4.85
5.35
Input Voltage (V)
Figure 5. Output Voltage vs. Load Current
Figure 6. Output Voltage vs. Input Voltage - Dropout
2.88
2.86
-40°C
2.87
+25°C
2.84
2.86
Output Voltage (V)
Output voltage (V)
+85°C
2.85
2.84
2.83
2.82
2.82
2.8
2.78
2.76
Iload = 100mA
2.74
2.81
2.8
0
25
50
75
2.72
2.75
100 125 150 175 200
Load Current (mA)
2.8
2.85
2.9
2.95
3
3.05
Input Voltage (V)
Figure 7. Dropout Voltage vs. Load Current
Figure 8. PSRR vs. Frequency
100
150
90
125
80
100
PSRR (dB)
Dropout Voltage (V)
Iload = 200mA
75
50
60
50
40
-40°C
25
70
+25°C
30
+85°C
0
25
50
75
100
125
150
175
200
20
100
Load Current (mA)
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1000
10000
100000
Frequency (Hz)
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AS1374
Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s
Figure 9. Ground Pin Current vs. Load Current
Figure 10. Ground Pin Current vs. Temperature
33
30
Ground Pin Current (µA)
Ground Pin Current (µA)
32
31
30
29
28
27
26
25
-40°C
29
28
27
26
+25°C
24
+85°C
23
0
25
50
75
100 125
150
175
25
-45 -30 -15
200
Load Current (mA)
Figure 11. Ground Pin Current vs. Input Voltage;
one Channel on, no Load
15
30
45
60
60
50
50
40
30
20
-40°C
10
+25°C
2
3
30
20
-40°C
10
+25°C
4
0
3.35
5
3.85
Input Voltage (V)
90
90
80
70
60
50
40
30
20
-40°C
+25°C
10
+85°C
0
3
4
5
Ground Pin Current (µA)
Ground Pin Current (µA)
100
2
5.35
80
70
60
50
40
30
20
-40°C
+25°C
10
0
3.35
Input Voltage (V)
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4.85
Figure 14. Ground Pin Current vs. Input Voltage;
both Channels on, ILOAD = 200mA
100
1
4.35
Input Voltage (V)
Figure 13. Ground Pin Current vs. Input Voltage;
both Channels on, no Load
0
90
+85°C
0
1
75
40
+85°C
0
60
Figure 12. Ground Pin Current vs. Input Voltage;
one Channel on, ILOAD = 200mA
Ground Pin Current (µA)
Ground Pin Current (µA)
0
Temperature (°C)
+85°C
3.85
4.35
4.85
5.35
Input Voltage (V)
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AS1374
Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s
Figure 15. Shutdown Current vs. Input Voltage
Figure 16. Load Regulation vs. Temperature
60
0
+25°C
50
Load Regulation (% / mA)
Shutdown Current (nA)
-40°C
+85°C
40
30
20
10
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
-0.0002
-0.0004
-0.0006
-0.0008
0
15 30
45
0.15
0.15
Line Regulation (% / V)
0.2
0.1
0.05
0
-0.05
-40°C
0.05
0
-0.05
Iload = 1mA
-0.1
Iload = 10mA
-0.2
-0.2
-45 -30 -15
100 125 150 175 200
Load Current (mA)
15
30
45
60
75
90
Figure 20. Load Transient Response near Dropout,
IOUT = 200mA
IOUT1
IOUT1
100mA/Div
VOUT2
10mV/Div
VOUT1
10mV/Div
Figure 19. Load Transient Response, Crosstalk,
between CH1 and CH2, IOUT = 200mA
VOUT1
0
Temperature (°C)
20mV/Div
75
Iload = 200mA
20µs/Div
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100mA/Div
50
Iload = 100mA
-0.15
+85°C
25
90
0.1
+25°C
0
75
Figure 18. Line Regulation vs. Temperature
0.2
-0.15
60
Temperature (°C)
Figure 17. Line Regulation vs. Load Current
Line Regulation (% / V)
CH2
-0.0012
-45 -30 -15
5.5
Input Voltage (V)
-0.1
CH1
-0.001
20µs/Div
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AS1374
Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s
EN1
IOUT1
50mA/Div
1V/Div
VOUT1
500mV/Div
VOUT1
VIN
2V/Div
Figure 22. Shutdown
10mV/Div
Figure 21. Line Transient Response
100µs/Div
100µs/Div
1V/Div
100mA/Div
VOUT1
IIN
EN1
1V/Div
EN1
VOUT1
IIN
100mA/Div
20µs/Div
20µs/Div
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2V/Div
Figure 24. Startup of CH1 when CH2 is On
2V/Div
Figure 23. Startup of CH1 when CH2 is Off
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AS1374
Datasheet - D e t a i l e d D e s c r i p t i o n
8 Detailed Description
The AS1374 is an ultra-low-noise, low-dropout, low-quiescent current linear-regulator with two seperated outputs specifically designed for space-limited applications. These device can supply loads up to 200mA. As shown in Figure 25,
the AS1374 consist of an integrated bandgap core, error amplifier, P-channel MOSFET pass transistor, and internal
feedback voltage-divider.
The output voltage is fed back through an internal resistor voltage-divider connected to pin OUT. Additional blocks
include a current limiter, thermal sensor, and enable logic.
Internal Voltage Reference
The bandgap reference is connected to the error amplifier’s inverting input. The error amplifier compares this reference
with the feedback voltage and amplifies the difference. If the feedback voltage is lower than the reference voltage, the
pass-transistor gate is pulled low. This allows more current to pass to the output and increases the output voltage. If
the feedback voltage is too high, the pass transistor gate is pulled high, allowing less current to pass to the output.
Internal P-Channel Pass Transistor
The AS1374 feature a 0.6Ω (typ) P-channel MOSFET pass transistor, which provides several advantages over similar
designs using a PNP pass transistor, including prolonged battery life. The P-channel MOSFET does not require a base
driver, thus quiescent current is dramatically reduced. The AS1374 do not exhibit problems associated with typical
PNP-based LDOs, and consume only 30µA of quiescent current in light load and 50µA in dropout (see Typical Operating Characteristics on page 5).
Output Voltage
The AS1374 deliver preset output voltages from 1.2V to 3.6V, in 50mV increments (see Ordering Information on page
13).
Enable
The AS1374 feature an actice high enable mode to shutdown each output indepentend. Driving EN 1 low disables Output 1, driving EN 2 low disables Output 2. The disabled Output enters a high-impedance state.
Figure 25. AS1374 - Block Diagram
-
EN 1
+
Enable Logic
CH1
OUT 1
Overcurrent
Protection CH1
VDD
Thermal
Protection
EN 2
Common
Logic
Bandgap
Trimmable
Reference
Enable Logic
CH2
+
AS1374
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GND
Overcurrent
Protection CH2
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OUT 2
-
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AS1374
Datasheet - D e t a i l e d D e s c r i p t i o n
Current Limit
The AS1374 include a current limiting circuitry to monitor and control the P-channel MOSFET pass transistor’s gate
voltage, thus limiting the device output current to 300mA.
Note: See Table 3 on page 4 for the recommended min and max current limits. The output can be shorted to ground
indefinitely without causing damage to the device.
Thermal Protection
Integrated thermal protection circuitry limits total power dissipation in the AS1374. When the junction temperature (TJ)
exceeds +160ºC, the thermal sensor signals the shutdown logic, turning off the P-channel MOSFET pass transistor
and allowing the device to cool down. The thermal sensor turns the pass transistor on again after the device’s junction
temperature drops by 15ºC, resulting in a pulsed output during continuous thermal-overload conditions.
Note: Thermal protection is designed to protect the devices in the event of fault conditions. For continuous operation,
do not exceed the absolute maximum junction temperature rating of +150ºC.
Operating Region and Power Dissipation
The AS1374 maximum power dissipation is dependant on the thermal resistance of the case and PCB, the temperature difference between the die junction and TAMB, and airflow rate.
Power dissipation across the device is calculated as:
PD = IOUT (VIN - VOUT)
(EQ 1)
The maximum power dissipation is calculated:
PDMAX = (TJ - TAMB)/θJA
(EQ 2)
Where:
TJ - TAMB is the temperature difference between the AS1374 die junction and the surrounding air;
θJA is the thermal resistance through the circuit board, copper traces, and other materials to the surrounding.
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AS1374
Datasheet - A p p l i c a t i o n I n f o r m a t i o n
9 Application Information
Capacitor Selection and Regulator Stability
For normal operation, use a 1µF capacitor at pin VDD and a 1µF capacitor at pin OUT. Larger input capacitor values
and lower ESR provide better noise rejection and line-transient response. Reduce output noise and improve load-transient response, stability, and power-supply rejection by using large output capacitors.
Note: Some ceramic dielectrics exhibit large capacitance and ESR variation with temperature. With dielectrics such
as Z5U and Y5V, it may be necessary to use a 2.2µF or larger output capacitor to ensure stability at temperatures below -10°C. With X7R or X5R dielectrics, 1µF is sufficient at all operating temperatures.
Noise, PSRR, and Transient Response
The AS1374 is designed to deliver ultra-low noise and high PSRR, as well as low dropout and low quiescent currents
in battery-powered systems. The power-supply rejection is 85dB at 1kHz and 50dB at 100kHz. (see Figure 8 on page
5).
When operating from sources other than batteries, improved supply-noise rejection and transient response can be
achieved by increasing the values of the input and output capacitors, and through passive filtering techniques.
The Figure 19, Figure 20 on page 7 and Figure 21 on page 8 show the AS1374 Load- and Line- Transient Responses.
Dropout Voltage
The AS1374 minimum dropout voltage determines the lowest usable supply voltage. In battery-powered systems, this
determines the useful end-of-life battery voltage.
Since the AS1374 use a P-channel MOSFET pass transistor, the dropout voltage is a function of drain-to-source onresistance (RDS(ON)) multiplied by ILOAD (see Figure 7 on page 5).
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AS1374
Datasheet - P a c k a g e D r a w i n g s a n d M a r k i n g s
10 Package Drawings and Markings
The devices are available in a 6-bump WLP package.
Figure 26. 6-bump WLP Package
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AS1374
Datasheet - O r d e r i n g I n f o r m a t i o n
11 Ordering Information
The devices are available as the standard products shown in Table 4.
Table 4. Ordering Information
Ordering Code
Marking
Output Voltage 1
Output Voltage 2
Delivery Form
Package
AS1374-BWLT-285
ASSH
2.85V
2.85V
Tape and Reel
6-bump WLP
AS1374-BWLT1833
ASSJ
1.8V
3.3V
Tape and Reel
6-bump WLP
AS1374-BWLT1218
ASSK
1.2V
1.8V
Tape and Reel
6-bump WLP
Non-standard devices from 1.2V to 3.6V are available in 50mV steps. For more information and inquiries contact
http://www.austriamicrosystems.com/contact
Note: All products are RoHS compliant and Pb-free.
Buy our products or get free samples online at ICdirect: http://www.austriamicrosystems.com/ICdirect
For further information and requests, please contact us mailto:sales@austriamicrosystems.com
or find your local distributor at http://www.austriamicrosystems.com/distributor
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AS1374
Datasheet
Copyrights
Copyright © 1997-2009, austriamicrosystems AG, Tobelbaderstrasse 30, 8141 Unterpremstaetten, Austria-Europe.
Trademarks Registered ®. All rights reserved. The material herein may not be reproduced, adapted, merged,
translated, stored, or used without the prior written consent of the copyright owner.
All products and companies mentioned are trademarks or registered trademarks of their respective companies.
Disclaimer
Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing
in its Term of Sale. austriamicrosystems AG makes no warranty, express, statutory, implied, or by description regarding
the information set forth herein or regarding the freedom of the described devices from patent infringement.
austriamicrosystems AG reserves the right to change specifications and prices at any time and without notice.
Therefore, prior to designing this product into a system, it is necessary to check with austriamicrosystems AG for
current information. This product is intended for use in normal commercial applications. Applications requiring
extended temperature range, unusual environmental requirements, or high reliability applications, such as military,
medical life-support or life-sustaining equipment are specifically not recommended without additional processing by
austriamicrosystems AG for each application. For shipments of less than 100 parts the manufacturing flow might show
deviations from the standard production flow, such as test flow or test location.
The information furnished here by austriamicrosystems AG is believed to be correct and accurate. However,
austriamicrosystems AG shall not be liable to recipient or any third party for any damages, including but not limited to
personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or
consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the
technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of
austriamicrosystems AG rendering of technical or other services.
Contact Information
Headquarters
austriamicrosystems AG
Tobelbaderstrasse 30
A-8141 Unterpremstaetten, Austria
Tel: +43 (0) 3136 500 0
Fax: +43 (0) 3136 525 01
For Sales Offices, Distributors and Representatives, please visit:
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