ASM811 Datasheet, PDF (1/10 Pages) Alliance Semiconductor Corporation – 4 Pin P Voltage Supervisor with Manual Reset

October 2003
ASM811, ASM812
rev 1.0
4 Pin µP Voltage Supervisor with Manual Reset
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.
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 V_CC down to 1.1V. The ASM812 has an active-
high RESET output. The reset comparator is designed to ignore
fast transients on V_CC. A debounced manual reset input allows
the user to manually reset the systems to bring them out of
locked state.
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.
Six voltage thresholds are available to support 3V to 5V
systems:
RESET THRESHOLD
Suffix
Voltage
L
4.63
M
4.38
J
4.00
T
3.08
S
2.93
R
2.63
Features
• New 4.0V threshold option
• 9µA supply current
• Monitor 5V, 3.3V and 3V supplies
• Manual reset input
• 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
• Computers and Controllers
• Embedded controllers
• Portable/Battery operated systems
• Intelligent instruments
• Wireless communication systems
• PDAs and handheld equipment
• Automotive systems
• Safety Systems
Typical Operating Circuit
V_CC
V_CC
MR RESET
(RESET)
GND
V_CC
µP
RESET (RESET)
Input
GND
Alliance Semiconductor
2575 Augustine Drive . Santa Clara, CA 95054 . Tel: [phone] . Fax: [phone] . www.alsc.com
Notice: The information in this document is subject to change without notice