forth order band pass filter

Shibin Varghese

Other Parts Discussed in Thread: TINA-TI

Hi Team,
I am designing a fourth-order bandpass filter and I got a pretty nice design from Ti's online filter design tool and is attached herewith.

My problem is can I make a fourth-order bandpass filter using a single op-amp only.
I've seen some forth order BPF using a single op-amp, but the data available is very limited.

bib.irb.hr/.../71375.cr1468.pdf

Hope you guys can help.

over 2 years ago

0 kai klaas69 over 2 years ago

Guru 140200 points

Hi Shibin,

perform a TINA-TI simulation and consider manufacturing tolerances of components by setting them as "control objects". Then you will see whether it will work or not. Also keep in mnd that with very high Qs -and Q=50 is a very high Q- the required open loop gain for stable performance will heavily rise resulting in the use of very high bandwidth OPAmps.

Kai

0 Michael Steffes over 2 years ago

Guru 47535 points

Yes, your target Q is very high for the venerable sallen Key implementation, you might review this information from an earlier discussion - that dual amplfier bandpass (DABP) does a great job for high Q's

https://e2e.ti.com/support/amplifiers-group/amplifiers/f/amplifiers-forum/778421/selection-of-opamp-for-narrow-band-active-band-pass-filter

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forth order band pass filter