Datasheet

PIN
NAME FUNCTION
MAX6746
MAX6747
MAX6748–
MAX6751
MAX6752
MAX6753
5 5 — WDS
Watchdog Select Input. WDS selects the watchdog mode. Connect
WDS to ground to select normal mode and the watchdog timeout
period. Connect WDS to V
CC
to select extended mode, multiplying the
basic timeout period by a factor of 128. A change in the state of WDS
clears the watchdog timer.
— — 5 SET1
Logic Input. SET1 selects the watchdog window ratio or disables the
watchdog timer. See Table 1.
6 6 6 WDI
Watchdog Input.
MAX6746–MAX6751: A falling transition must occur on WDI within
the selected watchdog timeout period or a reset pulse occurs. The
watchdog timer clears when a transition occurs on WDI or whenever
RESET is asserted. Connect SWT to ground to disable the watchdog
timer function.
MAX6752/MAX6753: WDI falling transitions within periods shorter than
t
WD1
or longer than t
WD2
force RESET to assert low for the reset
timeout period. The watchdog timer begins to count after RESET is
deasserted. The watchdog timer clears when a valid transition occurs
on WDI or whenever RESET is asserted. Connect SET0 high and SET1
low to disable the watchdog timer function. See the Watchdog Timer
section.
7 7 7 RESET
Push/Pull or Open-Drain Reset Output. RESET asserts whenever V
CC
or RESET IN drops below the selected reset threshold voltage (V
TH
or
V
RESET IN
, respectively) or manual reset is pulled low. RESET remains
low for the reset timeout period after all reset conditions are deasserted,
and then goes high. The watchdog timer triggers a reset pulse (t
RP
)
whenever a watchdog fault occurs.
8 8 8 V
CC
Supply Voltage. V
CC
is the power-supply input and the input for xed
threshold V
CC
monitor.
MAX6746–MAX6753 μP Reset Circuits with Capacitor-Adjustable
Reset/Watchdog Timeout Delay
www.maximintegrated.com
Maxim Integrated │ 6
Pin Description (continued)