Function generator is a type of testing equipment with the the ability to add a DC offset that can generate a variety of different waveforms (sine waves, sawtooth, triangular, square and pulses). It is used in applications where the use of a straightforward signal generator, which focuses more on producing good sine waves, is not be enough. Not every function generator is the same. Some of the more simple ones are designed to operate up to frequencies of around 100 kHz, while there are models that are able to operate at higher frequencies up to 10 or 20 MHz.
Aside from producing different waveforms, depending on the model, each function generator comes with different functions and controls, hence choose according to your application.
Frequency – Just like the name suggests, this is the control that allows you to alter the basic frequency settings. This allows you to change the way the waveform will repeat but it is not a part of choosing the waveform type.
Waveform Type – This is the control which basically allows you to switch between waveforms. Depending on the model you choose, the most common waveforms are sine wave, square wave, triangular wave, pulse waves and saw tooth waves.
DC Offset – This is the switch you will want to use if you want to alter the average voltage of a signal. Regardless if you are switching from 0V to ground, if you need to alter the voltage then this is the function you should look for.
Duty Cycle – Last but not least, this control allows you to change the ratio from high voltage to low voltage in a certain signal. This changes the cycle to change to a different waveform.
The different waveforms a function generator can produce
Sine Waves – A function generator will have the capability to produce the most standard output there is, the sine wave. This is probably the most standard type of waveform that comes in the standard sinusoidal shape.
Square Waves – This is a fairly simple wave to produce which means it comes with most function generators. The signal is simply moving from a high level to a lower level repeatedly.
Pulse Waves – This is another type of waveform that can be produced by a function generator. It is pretty similar to the square waveform but the space ratio between them is really what differs and sets them apart.
Triangular Waves – This again is another variety that seems to move from a high point to a low point in a certain shape and speed. It is once again produced by a function generator and moves a certain way which gives it its name.
Saw tooth Waves – This is very similar to the triangular waveform but the rise is actually faster than the fall of the wave. The timing of this wave creates an interesting pattern which is where it gets its name as it looks like a saw tooth pattern.