MAX6723AUTRHD4+T Maxim Integrated, MAX6723AUTRHD4+T Datasheet - Page 13

• Manufacturer Part Number: MAX6723AUTRHD4+T
• Description: Supervisory Circuits
• Manufacturer: Maxim Integrated
• Series: MAX6715A, MAX6716A, MAX6717A, MAX6718A, MAX6719A, MAX6720A, MAX6721A, MAX6722A, MAX6723A, MAX6724A, MAX6725A, MAX6726A, MAX6727A, MAX6728A, MAX6729A, MAX6797Ar

Specifications of MAX6723AUTRHD4+T

• Number Of Voltages Monitored: 3
• Monitored Voltage: 1.8 V to 5 V, 0.9 V to 3.3 V
• Undervoltage Threshold: 2.55 V, 1.275 V, Adjustable
• Overvoltage Threshold: 2.7 V, 1.35 V, Adjustable
• Output Type: Active Low, Open Drain
• Manual Reset: Not Resettable
• Watchdog: Watchdog
• Battery Backup Switching: No Backup
• Power-up Reset Delay (typ): 2240 ms
• Supply Voltage - Max: 5.5 V
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Package / Case: SOT-23
• Chip Enable Signals: No
• Maximum Power Dissipation: 696 mW
• Minimum Operating Temperature: - 40 C
• Power Fail Detection: No
• Supply Current (typ): 15 uA
• Supply Voltage - Min: 0.8 V

magnitude indicated (reset threshold overdrive). The
graph shows the maximum pulse width that a negative-
going V
a reset pulse to be issued. As the amplitude of the tran-
sient increases (i.e., goes farther below the reset
threshold), the maximum allowable pulse width
decreases. A 0.1µF bypass capacitor mounted close to
the V
Setting and resetting the watchdog input at different
points in the program, rather than “pulsing” the watch-
dog input high-low-high or low-high-low, helps the
watchdog timer to closely monitor software execution.
This technique avoids a “stuck” loop where the watch-
dog timer continues to be reset within the loop, keeping
the watchdog from timing out. Figure 6 shows an exam-
ple flow diagram where the I/O driving the watchdog
input is set high at the beginning of the program, set low
at the beginning of every subroutine or loop, then set
high again when the program returns to the beginning. If
the program should “hang” in any subroutine, the I/O is
continually set low and the watchdog timer is allowed to
time out, causing a reset or interrupt to be issued.
CC
CC
pin provides additional transient immunity.
Watchdog Software Considerations
transient may typically have without causing
Dual/Triple, Ultra-Low-Voltage, SOT23 µP
______________________________________________________________________________________
Figure 6. Watchdog Flow Diagram
Supervisory Circuits
SUBROUTINE
COMPLETED
SUBROUTINE OR
PROGRAM LOOP
SET WDI LOW
PROGRAM
SET WDI
RETURN
START
CODE
HIGH
SUBROUTINE
HANG IN
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