19-1867; Rev 2; 12/05
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
♦ Monitor Primary V
Supplies from +1.8V
CC
to +5.0V and Secondary V
from +0.9V to +2.5V
♦ User Adjustable RESET IN Down to +0.63V
(MAX6826/MAX6827/MAX6828)
Supplies
CC2
♦ 140ms (min) Reset Timeout Delay
♦ 1.6s Watchdog Timeout Period
♦ Manual Reset Input
♦ 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 the 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.
♦ Guaranteed Reset Valid Down to V
= +1.0V
CC
♦ Immune to Short Negative V
♦ No External Components
Transients
CC
♦ 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
Devices are available in both leaded and lead-free packaging.
Specify lead-free by replacing “-T” with “+T” when ordering.
TOP VIEW
Standard Versions Table*
RESET(RESET)
1
2
3
6
5
4
V
CC
MAX6826–
MAX6831
MAX6826/MAX6827/MAX6828
GND
MR
RESET IN/V
WDI
L
S
R
Z
V
CC2
SOT23-6
(RESET) MAX6827/MAX6830 ONLY
RESET IN FOR MAX6826/MAX6827/MAX6828 ONLY
*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.
V
FOR MAX6829/MAX6830/MAX6831 ONLY
CC2
Typical Operating Circuit, Threshold Suffix Guide, and
Selector Guide appear at end of data sheet.
Standard Versions Table continued 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.