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MIC1232_06 Datasheet, PDF (1/6 Pages) Micrel Semiconductor – μP Supervisory Circuit | |||
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MIC2755
MIC1232
µP Supervisory Circuit
Micrel, Inc.
General Description
The MIC1232 is a multifunction circuit which monitors mi-
croprocessor activity, external reset and power supplies in
microprocessor based systems. The circuit functions include
a watchdog time, power supply monitor, microprocessor reset,
and manual pushbutton reset input.
The power supply line is monitored with a comparator and
an internal voltage reference. /RST is forced low when an
out-of-tolerance condition exists and remains asserted for
at least 250ms after VCC rises above the threshold voltage
(4.5V or 4.75V). The /RST pin will remain logic low with VCC
as low as 1.4V.
The Watchdog input (/ST) monitors µP activity and will as-
sert /RST if no µP activity has occurred with in the watchdog
timeout period. The watchdog timeout period is selectable
with nominal period of 150, 600, 1200 milliseconds.
Features
⢠Power OK/Reset time delay, 250ms min.
⢠Watchdog timer, 150ms, 600ms, or 1.2s typical
⢠Precision supply voltage monitor, select between 5% or
10% of supply voltage
⢠Available in 8-pin surface mount (SO)
⢠Debounced External reset input
⢠Low supply current, <18µA typical
Applications
⢠Automotive systems
⢠Intelligent systems
⢠Critical microprocessor power monitoring
⢠Battery powered computers
⢠Controllers
Ordering Information
Part Number
Standard
Pb-Free
MIC1232N MIC1232NY
MIC1232M MIC1232MY
Temperature Range
â40ºC to +85ºC
â40ºC to +85ºC
Package
8-Pin PDIP
8-Pin SOIC
Typical Application
VCC
VCC TD
MIC1232
PBRST ST
RST
TOL GND
VCC
µP
I/O
RESET
Micrel, Inc. ⢠2180 Fortune Drive ⢠San Jose, CA 95131 ⢠USA ⢠tel + 1 (408) 944-0800 ⢠fax + 1 (408) 474-1000 ⢠http://www.micrel.com
January 2006
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MIC1232
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