MAX705–MAX708/MAX813L
Low-Cost, µP Supervisory Circuits
_______________General Description
The MAX705-MAX708/MAX813L microprocessor (µP)
supervisory circuits reduce the complexity and number
of components required to monitor power-supply and
battery functions in µP systems. These devices significantly improve system reliability and accuracy compared to separate ICs or discrete components.
The MAX705/MAX706/MAX813L provide four functions:
1) A reset output during power-up, power-down, and
brownout conditions.
2) An independent watchdog output that goes low if
the watchdog input has not been toggled within 1.6
seconds.
3) A 1.25V threshold detector for power-fail warning,
low-battery detection, or for monitoring a power supply other than +5V.
4) An active-low manual-reset input.
The MAX707/MAX708 are the same as the MAX705/
MAX706, except an active-high reset is substituted for
the watchdog timer. The MAX813L is the same as the
MAX705, except RESET is provided instead of RESET.
Two supply-voltage monitor levels are available: The
MAX705/MAX707/MAX813L generate a reset pulse when
the supply voltage drops below 4.65V, while the
MAX706/MAX708 generate a reset pulse below 4.40V.
All four parts are available in 8-pin DIP, SO and µMAX®
packages.
_______________________Applications
Computers
Controllers
Intelligent Instruments
Automotive Systems
Critical µP Power Monitoring
___________________________Features
o Available in Tiny µMAX Package
o Guaranteed RESET Valid at VCC = 1V
o Precision Supply-Voltage Monitor
4.65V in MAX705/MAX707/MAX813L
4.40V in MAX706/MAX708
o 200ms Reset Pulse Width
o Debounced TTL/CMOS-Compatible
Manual-Reset Input
o Independent Watchdog Timer—1.6s Timeout
(MAX705/MAX706)
o Active-High Reset Output
(MAX707/MAX708/MAX813L)
o Voltage Monitor for Power-Fail or Low-Battery
Warning
______________Ordering Information
PART
TEMP RANGE
MAX705CPA
0°C to +70°C
8 Plastic DIP
MAX705CSA
0°C to +70°C
8 SO
MAX705CUA
0°C to +70°C
8 µMAX
MAX705C/D
0°C to +70°C
Dice*
Ordering Information continued at end of data sheet.
* Dice are specified at TA = +25°C.
** Contact factory for availability and processing to MIL-STD-883.
Devices in PDIP, SO and µMAX packages are available in both
leaded and lead-free packaging. Specify lead free by adding
the + symbol at the end of the part number when ordering.
Lead-free not available for CERDIP package.
_________________Pin Configurations
TOP VIEW
µMAX is a registered trademark of Maxim Integrated Products, Inc.
MR
__________Typical Operating Circuit
VCC
8
2
MAX705
MAX706
MAX813L
PFI 4
UNREGULATED DC
MAX667
+5V DC LINEAR
REGULATOR
RESET
PFI
MAX705
WDO
MAX706
MR MAX813L PFO
PUSHBUTTON
SWITCH
7
RESET (RESET)
6
WDI
PFO
DIP/SO
µP
PFI
WDO
5
1
GND 3
VCC
PIN-PACKAGE
VCC
RESET
I/O LINE
NMI
INTERRUPT
MR
1
8
RESET
VCC
2
7
RESET
6
N.C.
5
PFO
GND 3
MAX707
MAX708
PFI 4
DIP/SO
( ) ARE FOR MAX813L ONLY.
Pin Configurations continued at end of data sheet.
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
19-4334; Rev. 9; 1/13
