MAX690A/MAX692A/
MAX802L/MAX802M/
MAX805L
Microprocessor Supervisory Circuits
General Description
The MAX690A/MAX692A/MAX802L/MAX802M/MAX805L
reduce the complexity and number of components
required for power-supply monitoring and batterycontrol functions in microprocessor (μP) systems. They
significantly improve system reliability and accuracy
compared to separate ICs or discrete components.
These parts provide four functions:
1) A reset output during power-up, power-down, and
brownout conditions.
2) Battery-backup switching for CMOS RAM, CMOS μP,
or other low-power logic.
3) A reset pulse if the optional watchdog timer has not
been toggled within 1.6s.
4) A 1.25V threshold detector for power-fail warning or
low-battery detection, or to monitor a power supply
other than +5V.
The parts differ in their reset-voltage threshold levels and
reset outputs. The MAX690A/MAX802L/MAX805L generate
a reset pulse when the supply voltage drops below 4.65V,
and the MAX692A/MAX802M generate a reset below 4.40V.
The MAX802L/MAX802M guarantee power-fail accuracies
to ±2%. The MAX805L is the same as the MAX690A except
that RESET is provided instead of RESET.
All parts are available in 8-pin DIP and SO packages.
The MAX690A/MAX802L are pin compatible with the
MAX690 and MAX694. The MAX692A/MAX802M are pin
compatible with the MAX692.
Features
●● Precision Supply Voltage Monitor:
4.65V for MAX690A/MAX802L/MAX805L
4.40V for MAX692A/MAX802M
●● Reset Time Delay: 200ms
●● Watchdog Timer: 1.6s Timeout
●● Battery-Backup Power Switching
●● 200μA Quiescent Supply Current
●● 50nA Quiescent Supply Current in BatteryBackup Mode
●● Voltage Monitor for Power-Fail or Low-Battery
Warning
●● Power-Fail Accuracy Guaranteed to ±2%
(MAX802L/M)
●● Guaranteed RESET Assertion to VCC = 1V
●● 8-Pin SO and DIP Packages
Ordering Information
PART
TEMP RANGE
MAX690ACPA
0°C to +70°C
8 Plastic DIP
PIN-PACKAGE
MAX690ACSA
0°C to +70°C
8 SO
MAX690AC/D
0°C to +70°C
Dice*
MAX690AEPA
-40°C to +85°C
8 Plastic DIP
MAX690AESA
-40°C to +85°C
8 SO
MAX690AMJA
-55°C to +125°C
8 CERDIP**
●● Battery-Powered Computers and Controllers
●● Intelligent Instruments
●● Critical μP Power Monitoring
Ordering Information continued at end of data sheet.
*Dice are specified at TA = +25°C
**Contact factory for availability and processing to MIL STD883. Devices in PDIP and SO packages are available in both
leaded and lead(Pb)-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.
Typical Operating Circuit
Pin Configurations
Applications
UNREGULATED
DC
R1
REGULATED +5V
VCC
0.1µF
VCC
PFI
R2
3.6V
LITHIUM
BATTERY
19-4333; Rev 5; 4/15
VBATT
RESET
MAX690A PFO
MAX802L
WDI
GND
TOP VIEW
RESET
µP
NMI
I/O LINE GND
VOUT
BUS
VCC
CMOS
RAM
GND
VOUT
1
VCC
2
GND 3
PFI 4
MAX690A
MAX692A
MAX802L
MAX802M
MAX805L
DIP/SO
( ) ARE FOR MAX805L ONLY.
8
VBATT
7
RESET (RESET)
6
WDI
5
PFO
