Electronics > Projects, Designs, and Technical Stuff

Diffrential amp design

(1/8) > >>

ali_asadzadeh:
Hi,
I have an old design and it's working perfectly, it's used in an Electromagnetic Flow Meter, the input sensor differential potentials is in uV ranges.

Now I want to redesign it with newer and cheaper parts, because I want to increase the performance, and use lower priced parts, also It would be very beneficial if i could do it in a single supply config and also If I could do it fully differential and remove the GND from the input sensor, currently I'm using AD620 part, But for the new design I prefer using normal op-amps or use Chinese parts! any Ideas are highly appreciated.  If I could do it under 1$ for total op-amps it would be perfect.

moffy:
Because of the micro volt signal level, I  would go with a true differential amp as your AD620, or risk getting swamped by low cmrr. But you don't need two, the second can be just a straight opamp.

Zero999:

--- Quote from: moffy on January 23, 2020, 08:10:17 am ---Because of the micro volt signal level, I  would go with a true differential amp as your AD620, or risk getting swamped by low cmrr. But you don't need two, the second can be just a straight opamp.

--- End quote ---
Yes, it's not possible to do this with a cheap op-amp, not without spending more on precision resistors. Accurately measuring microvolt signals is incompatible with low cost.

magic:
You can eat your cake and have it too: buy AD620 from AliExpress 8)

ali_asadzadeh:
 ::) :P :-[ :-X we have made a lot progress in the industry, why stick to some old and pricey tech!
Can a few these  zero-drift Precision OpAmps come in handy? Like GS8333
https://lcsc.com/product-detail/Precision-OpAmps_Gainsil-GS8333-TR_C431326.html

Navigation

[0] Message Index

[#] Next page

There was an error while thanking
Thanking...
Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod