[sdiy] Ladder filters using different different filter topologies.

[Lanterman, Aaron]

> On Feb 8, 2019, at 4:20 AM, Ben Riggs <benalog1977 at gmail.com> wrote:
> 
> Basically, I’m trying to nut out a Sallen-key filter using diodes as current controlled resistors in a ladder/differential topology to remove the CV-bleed… but I can’t help but think I’ve seen it before.

I don’t think it’s what you’re looking for, but I seem to recall that the Steiner-Parker filter is somewhat along those lines.

It’s also not what you’re looking for, but the GX-1 VCF is Sallen Key-is with a diode bridge control element.

Maybe you’re looking for the patents cited on Don’s page here?

http://www.till.com/blog/archives/2005/03/ladder_filter_v.html

Particularly:

https://patents.google.com/patent/US6084470

Aaron Lanterman, Prof. of ECE, Georgia Tech
My blog on Education and Innovation: https://edupocalypsenow.wordpress.com
My blog on Electronics and Programming: https://lantertronics.blogspot.com