MAX696/MAX697
Microprocessor Supervisory Circuits
General Description
Features
The MAX696 and MAX697 are supplied in 16-pin packages and perform six functions:
Ordering Information
The MAX696/MAX697 supervisory circuits reduce the
complexity and number of components required for
power-supply monitoring and battery-control functions
in microprocessor (μP) systems. These include μP reset
and backup-battery switchover, watchdog timer, CMOS
RAM write protection, and power-failure warning. The
MAX696/MAX697 significantly improve system reliability
and accuracy compared to that obtained with separate
ICs or discrete components.
1) A reset output during power-up, power-down, and
brownout conditions. The threshold for this “lowline”
reset is adjustable by an external voltagedivider.
2) A reset pulse if the optional watchdog timer has not
been toggled within a specified time.
3) Individual outputs for low-line and watchdog fault conditions.
4) The reset time may be left at its default value of 50ms,
or may be varied with an external capacitor or clock
pulses.
5) A separate 1.3V threshold detector for power-fail warning, low-battery detection, or to monitor a power supply
other than VCC.
The MAX696 also has battery-backup switching for CMOS
RAM, CMOS microprocessor, or other lowpower logic.
The MAX697 lacks battery-backup switching, but has
write-protection pins (CE IN and CE OUT) for CMOS
RAM or EPROM. In addition, it consumes less than 250
microamperes.
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Adjustable Low-Line Monitor and Power-Down Reset
Power-OK/Reset Time Delay
Watchdog Timer—100ms, 1.6s, or Adjustable
Minimum Component Count
1μA Standby Current
Battery-Backup Power Switching (MAX696)
On-Board Gating of Chip-Enable Signals (MAX697)
Separate Monitor for Power-Fail or Low-Battery
Warning
PART
TEMP RANGE
PIN-PACKAGE
MAX696C/D
0°C to +70°C
Dice
MAX696CPE
0°C to +70°C
16 PDIP
MAX696CWE
0°C to +70°C
16 Wide SO
MAX696EPE
-40°C to +85°C
16 PDIP
MAX696EJE
-40°C to +85°C
16 CERDIP
MAX696EWE
-40°C to +85°C
16 Wide SO
MAX696MJE
-55°C to +125°C
16 CERDIP
Ordering Information continued at end of data sheet.
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.
Pin Configurations
TOP VIEW
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Computers
Controllers
Intelligent Instruments
Critical μP Power Monitoring
Typical Operating Circuit appears at end of data sheet.
Pin Configurations continued at end of data sheet.
19-0829; Rev 5; 7/14
1
16
RESET
VOUT
2
15
RESET
VCC
3
14
WDO
GND
4
13
LLIN
BATT ON
5
12
N.C.
LOW LINE
6
11
WDI
OSC IN
Applications
VBATT
7
10
PFO
OSC SEL
8
9
PFI
MAX696
