The defined voltage thresholds that a digital system uses to distinguish between a 1 and a 0. If a signal falls between the valid high and low logic levels, it sits in an undefined region where gates may interpret it unpredictably or oscillate.
Heard on the job
We need a level shifter between the sensor and the processor because their logic levels are incompatible.
Related terms
Logic high
The higher of two voltage states used to represent a binary one in a digital circuit.
Logic low
The lower of two voltage states used to represent a binary zero in a digital circuit.
TTL
Transistor-transistor logic is a classic digital circuit design family built from bipolar junction transistors.
CMOS
Complementary metal-oxide-semiconductor is the dominant fabrication technology for integrated circuits.