Window Comparator With Independent Adjustments (HA2841, HA4905)
Application Note April 1998 AN9802
Introduction
Window comparators, or limit comparators as they are sometimes called, determine when the input
voltage is within a pre-selected range.
The output
voltage usually goes to a TTL high when the input
voltage is within the pre-selected range.
A typical window comparator circuit normally consists of two comparators with two reference adjustments: one for the low trip level, and one for the high trip level.
If the reference
voltages are derived from the same resistor divider string, hystersis can not be added without having the trip levels interact.
If the reference
voltages are indepen...