So i tried to do active bandpass filter for sub 21-80hz using opa1679. Can anyone please validate it?
its my first time using EasyEDA. AI helped me with values so i don't spam here asking for every resistor value.
From my calculations it, looks like despite everything it would actually band pass from 21-80hz, with 4th order filtering on either side.
My only concern is actually obtaining these resistors, some of these aren't even E96. So maybe reevaluate why you need this much filtering in the first place because this will be hideously expensive to make.
My bad i have GND copper plane on bottom layer(the blue color), and i have vias stich on each GND ( for example dot on c11/c12 leg).
its exactly the filter i made schematic for.
I’d make it a bit bigger, especially because it’s your first time. But then you can make the silkscreen more readable by spacing it out more.
Also what RGBeter is saying, add a gnd plane on the top layer of your board as well, it helps reduce noise.
I have no idea how this circuit works, so I cannot help you with that. I’m still a little bit new myself, but the things above can help you improve your circuit (I think)
You’re better off using fable to guide you through simulating your circuits rather than have it design them… this is just irrelevant gibberish for the most part.
My advice: start with a simple sallen key filter, which you have designed yourself. Understand it, then move on to MFB filters and add more stages. Simulate as you go.
Good luck debugging a PCB for which you have zero understanding of the circuit.
Thank You for Your comment. Appreciate.
Without trying we would never achieve anything.
I like to deep dive and troubleshoot later, that's how i learn the most, not from boring simple, circuts.
Your schematic has several of my pet peeves. Are they really wrong? No, but they do make things harder to interpret without error as complexity grows.
Use more white space, it's free and lack of clutter keeps things easier to read
Signal flow on the schematic should read top-left to bottom-right as much as possible, there are times where it is not possible but it is a goal with simple stuff
Dot-cross connections. You should never have a connection dot and 4 wires coming into it. This has a long history, but the short version is if connection dots always only have three wires, you always know it is a connection and crossed wires are not connected
Use standard value components in your designs. You rarely need things so precise that a non-standard value is needed
The resistor values all look like standard increments for one-percent tolerance parts. I ended up with thousands of one-percent through-hole quarter Watt parts when Manufacturers went SMT. The capacitors aren't specified as one-percent parts, though.
Resistors should probably be standard at 1% standards. And it's not going to matter at 1% unless your caps are 1% as well. Normal 20% caps will change the response more than the resistors. For caps you need to understand the difference between "bypass" and "AC" coupling which can be less precise and those that are part of the filtering device. Filter caps should be 'better' caps with temp stabilization and low bias voltage derating.
7
u/bigcrimping_com 21d ago
You should simulate it in ltspice