ASM705 Datasheet, PDF (1/15 Pages) Alliance Semiconductor Corporation – Low Power UP Supervisor Circuits

July 2004
ASM705 / 706 / 707 / 708
ASM813L
rev 1.2
Low Power µP Supervisor Circuits
General Description
Features
The ASM705 / 706 / 707 / 708 and AS813L are cost effective
CMOS supervisor circuits that monitor power-supply and
battery voltage level, and µP/µC operation.
The family offers several functional options. Each device
generates a reset signal during power-up, power-down and
during brownout conditions. A reset is generated when the
supply drops below 4.65V (ASM705/707/813L) or 4.40V
(ASM706/708). For 3V power supply applications, refer to the
ASM705P/R/S/T data sheet. In addition, the ASM705/706/813L
feature a 1.6 second watchdog timer. The ASM707/708 have
both active-HIGH and active-LOW reset outputs but no
watchdog function. The ASM813L has the same pin-out and
functions as the ASM705 but has an active-HIGH reset output.
A versatile power-fail circuit has a 1.25V threshold, useful in low
battery detection and for monitoring non-5V supplies. All
devices have a manual reset (MR) input. The watchdog timer
output will trigger a reset if connected to MR.
All devices are available in 8-pin DIP, SO and MicroSO
packages.
• Precision power supply monitor
•4.65V threshold (ASM705/707/813L)
•4.40V threshold (ASM706/708)
• Debounced manual reset input
• Voltage monitor
•1.25V threshold
•Battery monitor / Auxiliary supply monitor
• Watchdog timer (ASM705/706/813L)
• 200ms reset pulse width
• Active HIGH reset output (ASM707/708/813L)
• MicroSO package
Applications
• Computers and embedded controllers
• Portable/Battery-operated systems
• Intelligent instruments
• Wireless communication systems
• PDAs and hendheld equipment
• Automative Systems
• Safety Systems
Typical Operating Circuit
Unregulated DC
+5V Regulator
R₁
V_CC
RESET
(RESET)
PFI
ASM705 ^WDI
ASM706
R₂
(ASM813L) _WDO
MR
PFO
µP
V_CC
RESET
(RESET)
I/O LINE
NMI
INTERRUPT
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