Forum: Analog Circuits Bandpass Filter

Author: Walid Whx (w2016x)
Posted on:
Attached files:

Rate this post
0 useful
not useful
I'm having a difficult time figuring out how the attached bandpass 
filter works - what sets F0, Q and Gain. I think the two lower opamps 
centered at Vcc/2 are acting as integrators but I'm baffled by how the 
feedback is applied to set the filter's parameters. Thanks!

Author: Lutz vW (Guest)
Posted on:

Rate this post
0 useful
not useful
It is the popular KHN-topology with two inverting MILLER integrators. 
The output of one integrator is fed back to the pos. input of the gain 
stage, and the other outputis connected to the inverting opamp input.
Recommendation: Google for KHN filter (Kerwin-Huelsman-Newcomb).


Entering an e-mail address is optional. If you want to receive reply notifications by e-mail, please log in.

Rules — please read before posting

  • Post long source code as attachment, not in the text
  • Posting advertisements is forbidden.

Formatting options

  • [c]C code[/c]
  • [avrasm]AVR assembler code[/avrasm]
  • [code]code in other languages, ASCII drawings[/code]
  • [math]formula (LaTeX syntax)[/math]

Bild automatisch verkleinern, falls nötig
Note: the original post is older than 6 months. Please don't ask any new questions in this thread, but start a new one.