A function generator is a piece of electronic test equipment or software used in electrical engineering to generate different types of electrical waveforms over a wide range of frequencies. Unlike RF generators and some others that only create sine waves, the function generator is able to create repetitive waveforms with a number of common shapes, such as sine, square, triangular, sawtooth (ramp), and pulse output. Function generators are used in the development, test, and repair of electronic equipment. For example, they may be used as a signal source to test amplifiers or to introduce an error signal into a control loop. Function generators are primarily used for working with analog circuits, while related pulse generators are primarily used for working with digital circuits. Some function generators can also generate white or pink noise. More advanced function generators are called arbitrary waveform generators (AWG) and use direct digital synthesis (DDS) techniques to generate any waveform that can be described by a table of amplitudes and time steps.
Function generators are capable of producing a variety of commonly used repetitive waveforms, but they cannot be programmed to create additional waveforms. For that, an arbitrary waveform generator (AWG) is required. Function generators tend to be used mainly for working with analog circuits, and some of the common users and uses for function generators are electronic hobbyists, response and stimulus testing, in-circuit signal injection, frequency response characterization, electrical equipment and electronic repair, educational institutions, and research and development.
A simple function generator will typically create a triangular waveform whose frequency you can smoothly control. This triangular wave is utilized as the basis for all of the other outputs. The generation of the triangular wave occurs by charging and discharging a capacitor from a continual current source on a repetitive basis. This creates a voltage ramp that is linearly ascending and descending.
