austria
micro
systems
AS1357
Programmable Triple LDO
Product Brief
1997-2005, austriamicrosystems AG, 8141 Unterpremstaetten, Austria-Europe. All Rights Reserved.
www.austriamicrosystems.com
Revision 1.03
1 - 2
1 General Description
The AS1357 is a high-performance triple CMOS low-
dropout voltage regulator in a single 4x4 package. The
efficient set of programmable power supplies is opti-
mized to deliver the best compromise between quies-
cent current and regulator performance for mobile
phones, PDAs, MP3 players, and other battery powered
devices.
The one-time-programmable (OTP) function provides
greater design flexibility by allowing for independent pro-
gramming of the output voltage for each regulator on-
site. The OTP function allows for fast prototyping as well
as full-production in the field. Factory trimmed versions
are also available.
Stability is guaranteed with ceramic output capacitors of
only 1F (20% X5R) up to 4.7F (20% X5R). The
low equivalent series resistance (ESR) of these capaci-
tors ensures low output impedance at high frequencies.
Regulation performance is excellent even under low
dropout conditions, when the power transistor has to
operate in linear mode.
The low-noise performance allows direct connection of
noise sensitive circuits without additional filtering net-
works.
The AS1357 is available in a 12-pin QFN 4x4 package
or in a wafer bumping package.
Figure 1. Pinout Assignments (Top View)
2 Key Features
!
3 Independent Voltage Regulators with Shutdown
!
Output Current: 200mA each LDO
!
One Time Programmable Output Voltage
(User- or Factory-Trimmed)
!
Programmable Output Voltage Range: 1.8 to 3.3V in
0.1V Steps
!
Accuracy: 1.5%
!
PSRR: 70dB at 1kHz, 40dB at 100kHz
!
Line Regulation: 2mV
!
Load Regulation: 0.6mV
!
Supply Range: 3 to 5.5V
!
0.2V Dropout Voltage @ I = 200mA
!
Shutdown Current:
1A
!
Supply Current Without Load: 175A (typ)
!
Softstart for Low Inrush Current
!
Stable with low ESR Ceramic Capacitors from 1 to
4.7F
!
Low Noise 40V rms @10Hz to 100kHz Bandwidth
!
Thermal Protection
!
Over-Current Protection
!
Temperature Range: -40 to +85C
!
Wafer Bumping
!
QFN12 4x4, Pitch 0.8mm Package
3 Applications
The AS1357 is ideal for cordless and mobile phones,
MP3 players, CD and DVD players, PDAs, handheld
computers, digital cameras, and any other hand-held
battery-powered device.
AS1357
TRIM
V
DD
N/C
V
OUT3
V
OUT2
V
OUT1
V
DD
EN2
EN1
EN3
N/C
REF
10
11
12
6
5
4
1
2
3
9
8
7
GND (Exposed Pad)
13
AS1357
austria
micro
systems
Product Brief
1997-2005, austriamicrosystems AG, 8141 Unterpremstaetten, Austria-Europe. All Rights Reserved.
www.austriamicrosystems.com
Revision 1.03
2 - 2
Copyrights
Copyright 1997-2005, austriamicrosystems AG, Schloss Premstaetten, 8141 Unterpremstaetten, Austria-Europe.
Trademarks Registered . All rights reserved. The material herein may not be reproduced, adapted, merged, trans-
lated, 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. austriami-
crosystems 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.
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 tech-
nical 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
A-8141 Schloss Premstaetten, Austria
Tel: +43 (0) 3136 500 0
Fax: +43 (0) 3136 525 01
e-mail:
info@austriamicrosystems.com
For Sales Offices, Distributors and Representatives, please visit:
http://www.austriamicrosystems.com
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