Window detector

A window detector circuit, also called window comparator circuit or dual edge limit detector circuits is used to determine whether an unknown input is between two precise reference threshold voltages.

[1] It employs two comparators to detect over-voltage or under-voltage.

[3] Outputs behind a logic gate like AND detect the input as in range of the so-called "window" between upper and lower reference.

Window detectors are used in industrial alarms, level sensor and controls, digital computers and production-line testing.

[citation needed] If Uin is greater than Urefbot and Uin is lower than Ureftop then both comparators' outputs will swing to the logical high and turn on the AND gate output.