In a binary system, this is the voltage level that represents a boolean true or a digital 1. The exact voltage depends on the technology family; for classic 5V TTL, anything above 2.0 volts is considered high, while 3.3V CMOS systems typically require at least 2.4 volts.
Heard on the job
The microcontroller isn't booting because the reset pin is stuck at a logic high.
Related terms
Logic low
The lower of two voltage states used to represent a binary zero in a digital circuit.
Logic level
A specific voltage range that represents a distinct binary state 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.