The first thing we do after we capture/collect an analog or a digital signal is to filter it. Filtering can be analog or digital: between the two, digital filters are way more efficient. However, digital filters do not work very well if we do not use an analog filter module first. In other words, analog filters are mandatory no matter what!
Analog filters are built with electronic hardware components, while digital filters are best implemented in firmware. However, there are also hardware digital filters built with PLG (Programmable Logic Gates) when the speed factor is imperative.
The most basic roots of Digital Signal Processing (DSP) technology is using filters--of course, that is digital filters. DSP, however, is a late child, therefore it works as an improved version of the good old analog filtering techniques. If you intend to start working with DSP, you need to study analog filters very, very well first.
The simplified structure employed to present analog filters on this page is:
1. Types of Filters
2. Low-Pass Filters
3. High-Pass Filters
4. Band-Pass Filters
5. Band-Reject Filters
NOTE
The basic notions highlighted on this page are related to a few electronic design topics presented in the first part, Hardware Design, of LEARN HARDWARE FIRMWARE AND SOFTWARE DESIGN.