AMSCO AS1922-18

a u s t ri a m i c r o s y s t e m s
AS1920, AS1922
Product Brief
Tr i p l e - Vo l ta g e , M i c r o - P o w e r M i c r o p r o c e s s o r
Supervi s ory Ci rcuits
1 General Description
2 Key Features
The AS1920 and AS1922 microprocessor supervisory
circuits were designed to generate a reset when at least
one of the three monitored supply voltages falls below
its respective trip threshold.
These very-low-current (6.5µA, typ) devices maintain
reset for a minimum timeout period after all supplies
have stabilized. Guaranteed to be in the correct state for
VCC > +1.0V, these devices are perfect for multiple-voltage systems with low current requirements and strict
monitoring requirements.
The devices are available as the standard products
listed in Table 1.
Table 1. Standard Products
Model
Output Type
Supervisory Voltages
AS1920-18
Push/Pull
3V, 1.8V, Adjustable
AS1922-18
Open-Drain
3V, 1.8V, Adjustable
All devices monitor primary and secondary factorytrimmed voltages. Additionally, a third monitoring voltage
can be selected via an external resistor divider.
The AS1920 has an active-low push/pull reset output,
whereas the AS1922 has an active-low open-drain reset
output.
!
Simultaneous Triple-Voltage Monitoring
!
Very-Low Supply Current: 6.5µA
!
±1.5% Accuracy Over Temperature
!
Reset Time Delay: 200ms
!
Power Supply Transient Immunity
!
Guaranteed Reset for VCC3 ≥ 1V or VCC18 ≥ 1V
!
Active-Low Push/Pull Reset Output (AS1920)
!
Active-Low Open-Drain Reset Output (AS1922)
!
5-pin SOT23 Package
3 Applications
The AS1920 and AS1922 are available in a 5-pin
SOT23 package.
The devices are ideal for personal computers, notebooks, battery-powered systems, embedded controllers,
intelligent instruments, automotive systems, critical CPU
monitoring, and any multi-supply monitoring application.
Figure 1. Typical Application Diagram
3V
System
Logic
1.8V
2.5V
5
VCC3
4
0.1µF
www.austriamicrosystems.com
R1
130kΩ
1%
0.1µF
R2
100kΩ
1%
VCC18
AS1920/
AS1922
3
VCCA
Revision 0.65
1
RESETN
2
GND
1-2
austriam i c r o systems
AS1920, AS1922
Data Sheet
Copyrights
Copyright © 1997-2006, austriamicrosystems AG, Schloss Premstaetten, 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.
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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 lifesustaining 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
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
austriamicrosystems
www.austriamicrosystems.com
Revision 0.65
– a leap ahead
2-2