10 May 2010

Filter Calculator (and other calculators)

When designing a simple Sallen-Key active filter yesterday for my VLF receiver I found several useful web resources. One of the best is http://www.calculatoredge.com/index.htm#electronics that has a lot of useful calculators for electronics. I like the fact that when designing filters it asks you, and gives you, values in "real" numbers like nF and kohms. Some calculators ask you to give values in Farads and ohms to the power E-09 and similar and are obviously written by a college professor and not a real engineer who finds it hard to work these out!


LY2SS said...

Would be funny if one would dare to ask 3.3E-9 Farads capacitor at the part shop

Anonymous said...

This is free and good for filter design. David WB4ONA...

TI's FilterPro™ muultiple feedback (MFB), Sallen-Key, and fully differential active filter design program is a Windows application. This application designs MFB and Sallen-Key low-pass and high-pass filters using Voltage Feedback Op Amps, resistors and capacitors. It also supports a fully-differential version of the MFB circuit. This program includes Bessell, Butterworth, Chebychev, and linear phase filter types and can be used to design filters from 1 to 10 poles. The capacitor values in each stage can be either selected by the computer or entered by the designer. An "always on" prompt window provides context-sensitive help information to the user. The response of the filter is displayed on a graph, showing gain, phase and group delay over frequency. Allows for analysis of component tolerances and automatic insertion of common component tolerances.

Download FilterPro software


FilterPro Documentation