The MAX6821–MAX6825 are low-voltage microprocessor
(μP) supervisory circuits that combine voltage monitoring,
watchdog timer, and manual reset input functions in
a 5-pin SOT23 package. Microprocessor supervisory circuits
significantly improve system reliability and accuracy
compared to separate ICs or discrete components.
These devices assert a reset signal whenever the monitored
voltage drops below its preset threshold, keeping it
asserted for a minimum timeout period after VCC rises
above the threshold. In addition, a watchdog timer monitors
against code execution errors. A debounced manual
reset is also available. The MAX6821–MAX6825 monitor
voltages from +1.8V to +5.0V. These outputs are guaranteed
to be in the correct state for VCC down to +1.0V.
Nine preprogrammed reset threshold voltages are
available (see the Threshold Suffix Guide). The
MAX6821, MAX6822, and MAX6823 all have a manual
reset input and a watchdog timer. The MAX6821 has
push-pull RESET, the MAX6822 has open-drain RESET,
and the MAX6823 has push-pull RESET. The MAX6824
has a watchdog timer and both push-pull RESET and
push-pull RESET. The MAX6825 has a manual reset
input and both push-pull RESET and push-pull RESET.
The Selector Guide explains the functions offered in
this series of parts