ds1831bst-r Maxim Integrated Products, Inc., ds1831bst-r Datasheet - Page 10

• Manufacturer Part Number: ds1831bst-r
• Description: Ds1831, Ds1831a, Ds1831b Multisupply Micromonitor
• Manufacturer: Maxim Integrated Products, Inc.

The
microprocessor address signals, data signals, or control signals. When the microprocessor functions
normally, these signals would, as a matter of routine, cause the watchdog to be reset prior to time-out. To
guarantee that the watchdog timer does not time-out, a transition must occur at or less than the minimum
times shown in Table 1. A typical circuit example is shown in Figure 10. The watchdog timing is shown
in Figure 11.
The DS1831A watchdog function cannot be disabled. The watchdog strobe input must be strobed to avoid
a watchdog time-out however the watchdog status output can be disconnected yielding the same result.
WATCHDOG CIRCUIT EXAMPLE Figure 10
TIMING DIAGRAM — STROBE INPUT Figure 11
ST
input can be derived from many microprocessor outputs. The most typical signals used are the
ST
WDS
µP
V
SENSE1
INVALID
EDGES
t
R1
R2
ST
PBRST
GND
IN1
ST
5V
EDGES
VALID
DS1831
10 of 14
NMI1
WDS
TD
PBRST
t
TD
WD
3.3V
MIN
V
CC
10kW
INDETERMINATE
EDGES
MAX