MAX6884 View Datasheet(PDF) - Maxim Integrated
Part Name
Description
Manufacturer
MAX6884 Datasheet PDF : 34 Pages
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EEPROM-Programmable, Hex
Power-Supply Supervisory Circuits
WDO
The MAX6884/MAX6885 offer a separate output for the
watchdog timer system. WDO is active low and program-
mable for open-drain or weak pullup. Program WDO to
assert RESET when the watchdog timer expires. See the
Configuring the Watchdog Timer section for a complete
description of the watchdog timer system.
Configuring the Watchdog Timer
A watchdog timer monitors microprocessor (µP) soft-
ware execution for a stalled condition and resets the µP
if it stalls. The output of the watchdog timer (WDO) con-
nects to the reset input or a nonmaskable interrupt of
the µP. Program R15h to configure the watchdog timer
functions (see Table 8). The watchdog timer features
independent initial and normal watchdog timeout peri-
ods between 6.25ms and 102.4s (see Figure 4).
The initial watchdog timeout period (tWDI) is active
immediately after power-up, after a reset event takes
place, after enabling the watchdog timer, or after the
watchdog timer expires. The initial watchdog timeout
period allows the µP to perform its initialization process.
2.5V
VCC OR IN1–IN4
WDO
RESET
WDI
tD-PO tRP
*tWDI
tWD
*tWDI
RESET NOT DEPENDENT ON WDO
2.5V
VCC OR IN1–IN4
WDO
RESET
WDI
tD-PO tRP
*tWDI
tWD
tRP
*tWDI
*tWDI IS THE INITIAL WATCHDOG TIMEOUT PERIOD. WDO CONNECTED TO MR.
Figure 4. Watchdog Timing Diagrams
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