Definition
A type of integrated circuit in which the output signal varies in direct proportion to the input signal, used to handle continuously variable (analog) signals such as voltages from sensors, audio, or radio waveforms. Common examples include operational amplifiers, voltage regulators, and audio amplifiers found in avionics and instrument systems.
Plain English
A small electronic chip that takes an incoming signal and produces an output that smoothly tracks it -- bigger in, bigger out; smaller in, smaller out -- without chopping it into on/off steps.
Context Anchor
Seen in aircraft electronics, avionics, instrument systems, sensors, and maintenance descriptions of electronic components.
Derivation
Linear' comes from the Latin linea, meaning 'line.' If you graphed the input against the output, you would get a straight line -- the output rises and falls in step with the input. This contrasts with 'digital' circuits, which only recognize two states (on or off).
Why Pilots Care
They provide reliable amplification and conditioning of communication and navigation signals in aircraft electronics.
Analogy
Think of a dimmer switch rather than a simple light switch. A dimmer can vary the light smoothly from low to high; a linear integrated circuit works with electrical signals that can vary smoothly too.
Intuition Check
Linear does not mean the chip is physically straight. Here, it means the circuit responds to changing input in a smooth, proportional way instead of just switching fully on or fully off.
Example Sentence 1
The audio panel uses a linear integrated circuit to amplify the weak signal from the microphone before sending it to the headsets.
Example Sentence 2
During preflight checks the technician verified the linear integrated circuit was supplying clean power to the attitude indicator.