Datasheet

MAX16997/MAX16998
High-Voltage Watchdog Timers with
Adjustable Timeout Delay
10 ______________________________________________________________________________________
V
HYST
t
RESET
t
WP
t
CW
≤ t
WDI
≤ t
WP
t
CW
≤ t
WDI
≤ t
WP
THE THREE CONSECUTIVE RESET COULD BE CAUSED BY THREE
TIMEOUTS AS SHOWN HERE OR BY THREE WDI FALLING EDGE
OUTSIDE THE OPEN WINDOW, OR A COMBINATION OF ANY RESET
CONDITIONS EXCEPT V
RESETIN
DROPS TOO LOW.
t
OW
t = 0
t
CW
t
WP
t
RESET
t
RESET
t
RESET
t
WDI
t
WDI
t
WDI
t
WDI
t
WDI
t
WDI
t
WDI
t
WDI
V
RESETIN
V
IN
V
IN
= 1.1V
V
PON
WDI
ENABLE
RESET
RESET
WDT CLEARS AND
STARTS COUNTING
FROM O
WDI
t
WP
t
WP
Figure 5. Power-On Reset and Power-Down Reset for the MAX16998A/B/D
V
HYST
V
IN
= 1.1V
V
PON
V
IN
= V
ENABLE
V
RESETIN
V
RESET
t
RESET
Figure 6. Detailed Power-Up Sequence for the MAX16998A/B/D