This thread has been locked.
If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.
We are working on the development of a dual pH and dual Pt100 sensor interface for a fish farm tank control system.
The tank is expected to have about 75m3 of water, a number of pumps, and feeding systems that are expected to inject noise.
Since the distance between the two pH sensors is expected to be about 6m is it needed an isolation between the signal conditioning cirquits of the two sensors (like the attached cirquit)?
In the attached files we are two isolation approaches and the signal conditioning cirtquit for one sensor for the approach #1.
Thank you in advance,Isolation #1 & #2.pdf
Tank_Interface _ IN_pH.pdfNikos
I'm NOT a TI employee or related in any way to the company but if you want some free advice ... :)
I'd suggest you go for design option #2 for the simple fact that its easier to isolate digital signals with no issues than analog signals. There are plenty of good digital isolators that exists where you're digital signal will be transmitted unmolested by noise and RF interference.
Analog will not fair well in the presence of noise especially on long cable runs, even when you have a differential input configuration into your ADC to try to cancel out common mode noise. Pumps are extremely noisy and are well known RF noise polluters.
The AMC1200 adds more noise to the signal via extra bias, voltage offsets and distortion.
Its much easier to clean up a digital signal than an analog one.
Just my 2 cents...
- David Musoke
We are glad that we were able to resolve this issue, and will now proceed to close this thread.
If you have further questions related to this thread, you may click "Ask a related question" below. The newly created question will be automatically linked to this question.
In reply to DMM:
Thank you very much for your advice and your support...
We have designed our prototypes isolating analog parts in-between them and in-between our SBC (pretty much close to your advice).
We are waiting for the board production to assembly them and start the testing...
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with respect to these materials. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.