An oscillator is an electronic component used to generate a repeating electronic signal (usually a sine or square wave). The circuit it consists of is called an oscillator circuit. An electronic circuit or device that can convert direct current into alternating current signal output with a certain frequency. There are many types, which can be divided into self-excited oscillators and other-excited oscillators according to the oscillation excitation mode; according to the circuit structure, they can be divided into resistance-capacitor oscillators, inductor-capacitor oscillators, crystal oscillators, tuning fork oscillators, etc.; according to the output waveform, they can be divided into For sine wave, square wave, sawtooth wave and other oscillators.

An oscillator is simply a frequency source and is generally used in a phase-locked loop. In detail, it is a device that can convert direct current electric energy into alternating current electric energy without external signal excitation. Generally divided into two types: positive feedback and negative resistance. The so-called "oscillation" implies communication, and the oscillator includes a process and function that never oscillates to oscillate. A device that can complete the conversion from DC power to AC power can be called an "oscillator".