ASM706 Datasheet, PDF (1/16 Pages) Alliance Semiconductor Corporation – 3/3.3/4.0 V uP Supervisor Circuits

October 2003
ASM706 P/ R/ S/ T/ J
ASM708 R/ S/ T/ J
rev 1.0
3/3.3/4.0 V µP Supervisor Circuits
General Description
Features
The ASM706P/R/S/T/J and ASM708R/S/T/J 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 2.63V (ASM706P/R, ASM708R), 2.93V
(ASM706S, ASM708S), 3.08V (ASM706T, ASM708T) or 4.00
(ASM706J, ASM708J). In addition, the ASM706P/R/S/T/J
feature a 1.6 second watchdog timer. The watchdog timer
output will trigger a reset if connected to MR. Floating the WDI
input pin disables the watchdog timer.
The ASM708R/S/T/J have both active-HIGH and active-LOW
reset outputs but no watchdog function. The ASM706P has the
same pin-out and functions as the ASM706R but has an active-
HIGH reset output.
• Precision power supply minotor
•2.63V threshold (ASM706P/R, ASM708R)
•2.93V threshold (ASM706S, ASM708S)
•3.08V threshold (ASM706T, ASM708T)
•New 4.00V threshold (ASM706J , ASM708J)
• Debounced manual reset input
• Auxiliary voltage monitor comparator
•1.25V threshold
•Battery monitor / auxiliary supply monitor
• Watchdog timer (ASM706P/R/S/T/J)
•Watchdog can be disabled by floating WDI
• 200ms reset time delay
• Three reset signal options
•Active HIGH: ASM706P
•Active LOW: ASM706R/S/T/J
•Active HIGH and LOW outputs: ASM708R/S/T/J
• DIP, SO and MicroSO packages
• Guaranteed RESET assertion to V_CC = 1.1V
Applications
A versatile power-fail circuit, useful in checking battery levels
and non-5V supplies, has a 1.25V threshold. All devices have a
manual reset input. All devices are available in 8-pin DIP, SO
and the compact MicroSO packages. The MicroSO package
requires 50% less PC board area than the conventional SO
package.
• Computers and embedded controllers
• CTI applications
• Automotive systems
• Portable/Battery-operated systems
• Intelligent instruments
• Wireless communication systems
• PDAs and hand-held equipment
• Safety systems
Typical Operating Circuit
Unregulated DC
+3.3V Regulator
R₁
V_CC
PFI
ASM706 R/S/T
ASM708 R/S/T
RESET
(RESET)
WDI
R₂
(ASM706 P)
MR
WDO
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