19-1867; Rev 1; 1/02
Dual Ultra-Low-Voltage SOT23 µP Supervisors
with Manual Reset and Watchdog Timer
________________________Applications
Portable/BatteryPowered Equipment
Embedded Controllers
Intelligent Instruments
Automotive Systems
Critical µP Monitoring
Multivoltage Systems
Pin Configuration
Features
o Monitor Primary VCC Supplies from +1.8V
to +5.0V and Secondary VCC2 Supplies
from +0.9V to +2.5V
o User Adjustable RESET IN Down to +0.63V
(MAX6826/MAX6827/MAX6828)
o 140ms (min) Reset Timeout Delay
o 1.6s Watchdog Timeout Period
o Manual Reset Input
o Three Reset Output Options
Push-Pull RESET
Push-Pull RESET
Open-Drain RESET
o Guaranteed Reset Valid Down to VCC = +1.0V
o Immune to Short Negative VCC Transients
o No External Components
o Small 6-pin SOT23 Packages
Ordering Information
PART†
TEMP RANGE
PIN-PACKAGE
MAX6826_UT-T
-40°C to +125°C
6 SOT23-6
MAX6827_UT-T
-40°C to +125°C
6 SOT23-6
MAX6828_UT-T
-40°C to +125°C
6 SOT23-6
MAX6829_ _UT-T
-40°C to +125°C
6 SOT23-6
MAX6830_ _UT-T
-40°C to +125°C
6 SOT23-6
MAX6831_ _UT-T
-40°C to +125°C
6 SOT23-6
†Insert the desired suffix letter (from Standard Versions table) into
the blanks to complete the part number.
Standard Versions Table*
TOP VIEW
MAX6826/MAX6827/MAX6828
RESET(RESET) 1
GND 2
6
MAX6826–
MAX6831
VCC
L
S
5
RESET IN/VCC2
4
WDI
R
Z
MR 3
SOT23-6
(RESET) MAX6827/MAX6830 ONLY
RESET IN FOR MAX6826/MAX6827/MAX6828 ONLY
VCC2 FOR MAX6829/MAX6830/MAX6831 ONLY
V
*Samples are typically available for standard versions only.
The MAX6826/MAX6827/MAX6828 require a 2.5k minimum
order increment for all versions. Contact factory for availability.
Typical Operating Circuit appears at end of data sheet.
Standard Versions Table continued at end of data sheet.
Threshold Suffix Guide appears at end of data sheet.
Selector Guide appears at end of data sheet.
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX6826–MAX6831
General Description
The MAX6826–MAX6831 are ultra-low-voltage microprocessor (µP) supervisory circuits designed to monitor
two power supplies and have manual reset and watchdog input functions. These devices assert a system reset
if any of the monitored supplies fall below the preprogrammed thresholds, and maintain reset for a minimum
timeout period after the supplies rise above the threshold.
Microprocessor supervisors significantly improve system
reliability and accuracy compared to separate ICs or discrete components. These devices monitor primary voltages from +1.8V to +5.0V and secondary voltages from
+0.9V to +2.5V. These devices are guaranteed to be in
the correct state for VCC down to +1.0V.
A variety of preprogrammed reset threshold voltages
are available (see Threshold Suffix Guide). The devices
include manual reset and watchdog inputs. The
MAX6829/MAX6830/MAX6831 provide a factorytrimmed threshold to monitor a 2nd voltage down to
+0.9V. The MAX6826/MAX6829 have a push-pull
RESET, the MAX6827/MAX6830 have a push-pull
RESET and the MAX6828/MAX6831 have an open-drain
RESET. The MAX6826/MAX6827/MAX6828 have an auxiliary monitor that allows user adjustable input to monitor
voltages down to +0.6V. See Selector Guide for functions available.
