Low Pass Filters: An Introduction With FAQs
Circuit boards and circuit systems make up a lot of the electronic systems that society relies on today, but understanding these complex systems requires understanding the components necessary. One such component is the low-pass filter like the Butterworth low-pass filter. Here is a short introduction.
Why are low-pass filters used?
Low-pass filters are used in circuitry applications when there are components or sensors inside that can be overly sensitive to noise generated as part of an electrical signal. For example, if a circuit is utilizing both AC and DC voltage, noise radiating from the AC voltage may cause interference with DC voltage, which tends to be far cleaner when it comes to noise. A circuit board can have what is referred to as decoupling capacitors, which can eradicate some levels of noise, but if the circuit board is larger, there are limitations on how many of these capacitors can be implemented effectively. Therefore, a low-pass filter may have to be used for a broader-scale noise reduction.
What should you be looking for in a well-designed low-pass filter?
There are specific low-pass filters that are always preferable when it comes to functionality. In general, the best low-pass filters are going to provide noise reduction with little frequency interference. Some lower-quality filters generate ripples in an electrical signal as the noise is canceled out, and this is one of the things that Butterworth low-pass filters are known to avoid.
What is the difference between a capacitive and an inductive low-pass filter?
Capacitive and inductive low-pass filters are quite different from one another, and each serves its own purpose in an electrical circuit setup. The inductive low-pass filter is simple; it has only one small filter. The capacitive low-pass filter most often boasts both a component for the filter itself and a resistor, but these filters can also be far more complex with other components and actions.
What exactly is the cutoff frequency of a low-pass filter?
The cutoff frequency for different filter models can actually vary depending on the build. The cutoff, such as with Butterworth filters, is going to happen when reactance equals resistance where ohms measurement is concerned. It is important to look at the cut-off rating for any filter you plan to use in your circuit setup to make sure it will serve the purpose properly.
Reach out to a tech supplier to learn more about low pass filters and how they could benefit your systems.