ASM1832 Datasheet, PDF (1/9 Pages) Alliance Semiconductor Corporation – 3.3V UP Power Supply Monitor and Reset Circuit

ASM1832
3.3 V mP Power Supply
Monitor and Reset Circuit
Description
The ASM1832 is a fully integrated microprocessor supervisor. It
can halt and restart a “hung−up” microprocessor, restart a
microprocessor after a power failure. It has a watchdog timer and
external reset override. RESET and RESET outputs are push−pull.
A precision temperature−compensated reference and comparator
circuits monitor the 3.3 V, V_CC input voltage status. During power−up
or when the V_CC power supply falls outside selectable tolerance
limits, both RESET and RESET become active. When V_CC rises
above the threshold voltage, the reset signals remain active for an
additional 250 ms minimum, allowing the power supply and system
microprocessor to stabilize. The trip point tolerance signal, TOL,
selects the trip level tolerance to be either 10% or 20%.
A debounced manual reset input, PBRST, activates the reset outputs
for a minimum period of 250 ms. There is a watchdog timer to stop and
restart a microprocessor that is “hung−up”. The watchdog timeouts
periods are selectable: 150 ms, 610 ms, and 1200 ms. If the ST input is
not strobed LOW before the time−out period expires, a reset is
generated.
Devices are available in 8−pin PDIP, 8−pin SO and compact 8−pin
MicroSO packages.
Features
• 3.3 V Supply Monitor
• Push−pull Output
• Selectable Watchdog Period
• Debounce Manual Push−button Reset Input
• Precision Temperature−compensated Voltage Reference and
Comparator
• Power−up, Power−down and Brown Out Detection
• 250 ms Minimum Reset Time
• Active LOW and HIGH Reset Signal
• Selectable Trip Point Tolerance: 10% or 20%
• Low−cost 8−pin DIP/SO and 8−pin Micro SO Packages
• Wide Operating Temperature: −40°C to +85°C
Applications
• Microprocessor Systems
• Computers
• Controllers
• Portable Instruments
• Automotive Systems
http://onsemi.com
PDIP−8
NO SUFFIX
CASE 646AA
MICRO−8
U SUFFIX
CASE 846AA
SOIC−8
S SUFFIX
CASE 751BD
PIN CONFIGURATION
1
PBRST
TD
ASM1832
TOL
V_CC
ST
RESET
GND
RESET
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 9 of this data sheet.
© Semiconductor Components Industries, LLC, 2011
1
August, 2011 − Rev. 3
Publication Order Number:
ASM1832/D