ASM811, ASM812
October 2003
rev 1.0
4 Pin µP Voltage Supervisor with Manual Reset
Six voltage thresholds are available to support 3V to 5V
systems:
General Description
The ASM811/ASM812 are cost effective low power supervisors
designed to monitor voltage levels of 3.0V, 3.3V and 5.0V
power supplies in low-power microprocessor (µP),
microcontroller (µC) and digital systems. They provide excellent
reliability by eliminating external components and adjustments.
RESET THRESHOLD
Suffix
Voltage
4.63
L
M
J
4.38
4.00
A reset signal is issued if the power supply voltage drops below
a preset reset threshold and is asserted for at least 140ms after
the supply has risen above the reset threshold. The ASM811
has an active-low output RESET that is guaranteed to be in the
correct state for VCC down to 1.1V. The ASM812 has an active-
T
S
R
3.08
2.93
2.63
high RESET output. The reset comparator is designed to ignore
fast transients on VCC. A debounced manual reset input allows
Features
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New 4.0V threshold option
the user to manually reset the systems to bring them out of
locked state.
9µA supply current
Monitor 5V, 3.3V and 3V supplies
Manual reset input
Low power consumption makes the ASM811/ASM812 ideal for
use in portable and battery operated equipment. The ASM811/
ASM812 are available in a compact 4-pin SOT-143 package
and thus use minimal board space.
140ms min. reset pulse width
Guaranteed over temperature
Active-low reset valid with 1.1V supply (ASM811)
Small 4-pin SOT-143 package
No external components
Power-supply transient-immune design
Applications
Typical Operating Circuit
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Computers and Controllers
Embedded controllers
Portable/Battery operated systems
Intelligent instruments
VCC
Wireless communication systems
PDAs and handheld equipment
Automotive systems
VCC
VCC
µP
Safety Systems
RESET
Input
(RESET)
RESET
MR
(RESET)
GND
GND
Alliance Semiconductor
2575 Augustine Drive . Santa Clara, CA 95054 . Tel: 408.855.4900 . Fax: 408.855.4999 . www.alsc.com
Notice: The information in this document is subject to change without notice
ALSC [ ALLIANCE SEMICONDUCTOR CORPORATION ]
