Filters Tutorial Episode 9: The Sallen-Key Second Order Active Filters

[@Bnels]

This is one of the best tutorials I have watched. Thank you so much!

[@raefsiam]

good work , thank you

[@Coolgiy67]

Extremely good video

[@eleneasy]

Thanks

[@mirunavlasceanu706]

Thank you so much, it helped me so much!

[@eleneasy]

I'm so glad!

[@mirunavlasceanu706]

@@eleneasy I also got a question, It's okay to cascade two second-order circuits (with the same capacitor and resistor values) to achieve a fourth-order filter? or it will impact da quality factor?

[@eleneasy]

@@mirunavlasceanu706 Yes, as long as they are active filters, you can cascade two second order filters to make a fourth order filter. However, the quality factor, or Q, also changes. In particular, if you use two identical second order filters, the new Q factor becomes sqrt(2) times (about 1.41) the original Q factor of each filter. If the two filters are different, then it is necessary to study the transfer function of the newly formed 4th order filter to understand how the Q changes.