19-2523; Rev 0; 7/02
Microprocessor Supervisory Reset Circuits
with Edge-Triggered, One-Shot Manual Reset
General Description
The MAX6467/MAX6468 microprocessor (碌P) supervi-
sory circuits monitor single power-supply voltages from
+1.8V to +5.0V and assert a reset if the supply voltage
drops below its preset threshold. An edge-triggered,
one-shot manual reset function ensures that the 碌P
enters the reset mode for a fixed timeout period only,
even in the event of a continuously asserted manual
reset. The MAX6467/MAX6468 significantly improve
system reliability compared to traditional manual reset
supervisory circuits.
A variety of factory-trimmed threshold options accommo-
date different supply voltages and tolerances, eliminating
external components. The factory-set thresholds range
from +1.575V to +4.625V to monitor +5.0V, +3.3V, +3.0V,
+2.5V, and +1.8V supplies with various tolerances. Reset
timeout periods of 150ms (min) and 1200ms (min) are
available to accommodate different 碌P platforms.
A single, active-low
RESET
output asserts when V
CC
drops below its threshold or if the edge-triggered
MR
asserts low.
RESET
remains low for the reset timeout
period after V
CC
rises above its threshold and for a fixed,
one-shot timeout period after a manual reset input falling
edge.
RESET
remains valid as long as V
CC
remains
above +1V. Open-drain (MAX6467) and push-pull
(MAX6468) output options provide additional flexibility in
the system design.
The MAX6467/MAX6468 are offered in the space-saving
4-pin SOT143 package and the ultra-small 4-pin SC70
package and are specified over the automotive (-40掳C to
+125掳C) temperature range.
Features
o
Precision Factory-Set Reset Threshold Voltages
for +5.0V, +3.3V, +3.0V, +2.5V, and +1.8V Supplies
o
Edge-Triggered Manual Reset Input with One-
Shot Pulsed Reset Output
o
Two Reset Timeout Period Options (150ms or
1200ms min)
o
Immune to Short Voltage Transients
o
Low Supply Current (3碌A at V
CC
= +1.8V)
o
RESET
Valid to V
CC
= +1V
o
Active-Low Open-Drain and Push-Pull
RESET
Output Options
o
-40掳C to +125掳C Operating Temperature Range
o
Small 4-Pin SC70 and SOT143 Packages
o
No External Components Required
o
Pin Compatible with MAX811, MAX6315,
MAX6384, and MAX6386
MAX6467/MAX6468
Ordering Information
PART
MAX6467XS_
_D_-T
MAX6467US_ _D_-T
MAX6468XS_
_D_-T
MAX6468US_ _D_-T
TEMP RANGE
-40掳C to +125掳C
-40掳C to +125掳C
-40掳C to +125掳C
-40掳C to +125掳C
PIN-PACKAGE
4 SC70-4
4 SOT143-4
4 SC70-4
4 SOT143-4
Applications
Cell Phones/PDAs
Embedded Control Systems
Industrial Equipment
Automotive Products
Portable/Battery-Powered Equipment
Medical Devices
DSL Modems
MP3 Players
GPS Systems
Digital Cameras
Note:
Insert reset threshold suffix (see Reset Threshold table)
after XS or US. Insert reset timeout delay (see Reset Timeout
Delay table) after D to complete the part number. Sample stock
is generally held on standard versions only (see Standard
Versions table). Standard versions have an order increment
requirement of 2500 pieces. Nonstandard versions have an
order increment requirement of 10,000 pieces. Contact factory
for availability.
Pin Configurations
TOP VIEW
GND 1
4
V
CC
MR
RESET 2
MAX6467XS
MAX6468XS
SC70
3
Typical Operating Circuit appears at end of data sheet.
Pin Configurations continued at end of data sheet.
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________________________________________________________________
Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim鈥檚 website at www.maxim-ic.com.
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