19-1867; Rev 1; 1/02
Dual Ultra-Low-Voltage SOT23 µP Supervisors
with Manual Reset and Watchdog Timer
General Description
Features
The MAX6826–MAX6831 are ultra-low-voltage micro-
processor (µP) supervisory circuits designed to monitor
two power supplies and have manual reset and watch-
dog input functions. These devices assert a system reset
if any of the monitored supplies fall below the prepro-
grammed 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 dis-
crete components. These devices monitor primary volt-
ages from +1.8V to +5.0V and secondary voltages from
+0.9V to +2.5V. These devices are guaranteed to be in
o Monitor Primary V
Supplies from +1.8V
CC
to +5.0V and Secondary V
from +0.9V to +2.5V
o User Adjustable RESET IN Down to +0.63V
(MAX6826/MAX6827/MAX6828)
Supplies
CC2
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
the correct state for V down to +1.0V.
CC
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 factory-
trimmed 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 aux-
iliary monitor that allows user adjustable input to monitor
voltages down to +0.6V. See Selector Guide for func-
tions available.
o Guaranteed Reset Valid Down to V
= +1.0V
CC
o Immune to Short Negative V
Transients
CC
o No External Components
o Small 6-pin SOT23 Packages
Ordering Information
†
PART
TEMP RANGE
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
PIN-PACKAGE
6 SOT23-6
6 SOT23-6
6 SOT23-6
6 SOT23-6
6 SOT23-6
6 SOT23-6
MAX6826_UT-T
MAX6827_UT-T
MAX6828_UT-T
MAX6829_ _UT-T
MAX6830_ _UT-T
MAX6831_ _UT-T
________________________Applications
Portable/Battery-
Powered Equipment
Automotive Systems
Critical µP Monitoring
Multivoltage Systems
Embedded Controllers
Intelligent Instruments
†
Insert the desired suffix letter (from Standard Versions table) into
the blanks to complete the part number.
Pin Configuration
Standard Versions Table*
TOP VIEW
MAX6826/MAX6827/MAX6828
RESET(RESET)
1
2
3
6
5
4
V
CC
L
S
R
Z
V
MAX6826–
MAX6831
GND
MR
RESET IN/V
WDI
CC2
*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.
SOT23-6
(RESET) MAX6827/MAX6830 ONLY
RESET IN FOR MAX6826/MAX6827/MAX6828 ONLY
V
FOR MAX6829/MAX6830/MAX6831 ONLY
CC2
Typical Operating Circuit appears at end of data sheet.
Threshold Suffix Guide appears at end of data sheet.
Standard Versions Table continued at end of data sheet.
Selector Guide appears at end of data sheet.
________________________________________________________________ Maxim Integrated Products
1
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.