AC Coupled Single Supply Comparator

AC coupled single supply comparator. Sometimes a single supply comparator is required to use ac coupling to detect sine waves or square waves. Often this is needed due to differences in ground potential between two different modules. Whenever ac coupling is involved in single supply circuitry, negative voltages become a concern. Excessive negative voltages on comparators can cause the comparator to trip erroneously or to become stuck at unpredictable levels