MAX696MJE/883B Maxim Integrated Products, MAX696MJE/883B Datasheet - Page 9

• Manufacturer Part Number: MAX696MJE/883B
• Description: Supervisory Circuits MPU Supervisor
• Manufacturer: Maxim Integrated Products

Specifications of MAX696MJE/883B

• Monitored Voltage: 3 V to 5.5 V
• Output Type: Active High, Active Low, Push-Pull
• Manual Reset: Not Resettable
• Watchdog: Watchdog
• Battery Backup Switching: Backup
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 3 V
• Supply Current (typ): 300 uA
• Maximum Power Dissipation: 600 mW
• Maximum Operating Temperature: + 125 C
• Mounting Style: Through Hole
• Package / Case: CDIP-16
• Minimum Operating Temperature: - 55 C
• Power Fail Detection: Yes
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

The MAX696 operates with battery voltages from 2.0V
to 4.25V. The battery voltage should not be within 0.5V
of V
tors, either standard electrolytic or the farad-size dou-
ble-layer capacitors, can also be used for short-term
memory backup. The capacitor charging voltage
should include a diode to limit the fully charged voltage
to approximately 0.5V less than V
resistor for rechargeable batteries should be connect-
ed to V
exists if the resistor is connected to V
A small leakage current of typically 10nA (20nA max)
flows out of the V
the amount of current that is drawn from V
polarity is such that the backup battery is always slight-
ly charged, and is never discharged while V
operating voltage range. This extends the shelf life of
the backup battery by compensating for its self-dis-
charge current. Also note that this current poses no
problem when lithium batteries are used for backup
since the maximum current (20nA) is safe for even the
smallest lithium cells.
Figure 4. Reset Block Diagram
CC
, or switchover may occur. High-value capaci-
OUT
LL
IN
since this eliminates the discharge path that
(MAX697) CE IN
BATT
_______________________________________________________________________________________
terminal. This current varies with
13V
Microprocessor Supervisory Circuits
+
-
CC
CC
WATCHDOG
WATCHDOG
TIMER
FROM
. The charging
.
OUT
CC
, but its
is in its
V
CC
RESET
POWER-ON
RESET
If the battery-switchover section is not used, connect
V
shows the state of the inputs and output in the low-
power battery-backup mode.
RESET is an active-low output that goes low whenever
LL
above 1.312V for 50ms. (See Figures 4 and 5.)
The guaranteed minimum and maximum low-line thresh-
olds of the MAX696/MAX697 are 1.2V and 1.4V. The
LL
The response time of the reset voltage comparator is
about 100µs. LL
glitches do not activate the RESET output.
RESET also goes low if the watchdog timer is enabled
and WDI remains either high or low longer than the
watchdog timeout period. RESET has an internal 3µA
pullup, and can either connect to an open-collector
reset bus or directly drive a CMOS gate without an
external pullup resistor.
BATT
IN
IN
RESET
TIME
comparator has approximately 12mV of hysteresis.
falls below 1.3V. It remains low until LL
to GND and connect V
IN
Q
n
should be bypassed to ensure that
FROM TIMEBASE
10kHz CLOCK
SECTION
OUT
CE OUT (MAX697)
LOW LINE
RESET
RESET
to V
Reset Output
CC
. Table 2
IN
rises
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