MIC811 Datasheet, PDF (1/8 Pages) Micrel Semiconductor – Microprocessor Reset Circuits

MIC811/MIC812 Microprocessor Reset Circuits
MIC811/MIC812
Microprocessor Reset Circuits
Description
The MIC811/MIC812 are inexpensive microprocessor
supervisory circuits that monitor power supplies in
microprocessor based systems.
The function of these devices is to assert a reset if
either the power supply drops below a designated reset
threshold level or MR is forced low. Several different
reset threshold levels are available to accomodate 3V,
3.3V or 5V powered systems.
The MIC811 has an active low RESET output, while the
MIC812 offers an active high RESET output. The reset
output is guaranteed to remain asserted for a minimum
of 140ms after VCC has risen above the designated
reset threshold level. The MIC811/MIC812 come in a 4-
pin SOT-143 package.
Typical Applications
· ^{Portable Equipment}
· ^{Intelligent Instruments}
· ^{Critical Microprocessor Power Monitoring}
· ^{Printers/Computers}
· ^Controllers
Reset Threshold
Voltage (V)
4.63
4.38
4.00
3.08
2.93
2.63
Device
Suffix
L
M
J
T
S
R
Ordering Information
Part
MIC811_U
MIC812_U
Package
4-Lead SOT-143
4-Lead SOT-143
Temp. Range
-40°C to +85°C
-40°C to +85°C
Place the device suffix of desired reset threshold voltage from table above in
blank to complete the part number.
Pin Configuration
Top View
GND 1
RESET 2
MIC81 1
4 VCC
3 MR
GND 1
RESET 2
MIC812
4 VCC
3 MR
Features
· RESET Remains Valid with VCC as Low
as 1.4V
· Precision Voltage Monitor for 3V, 3.3V
or 5V Power Supplies
· ^{Available in 4-Pin SOT-143 Package}
· ^{<15µA Supply Current}
· ^{140ms Minimum Reset Pulse Width}
· ^{Manual Reset Input}
Typical Operating Circuit
VCC
VCC
MIC81 1
RESET
MR
VCC
µP
RESET
1