Hello, I’m designing a logger to collect data from a thermocouple (may be any type) using Raspberry Pico (3.3V). I want to isolate analog pins but signal should be proportional to the input signal. As per my study inductive isolation can be done to transfer power, proportional to the input analog signal.

Suggest a reliable way of isolation and ICs as per my requirement. Please mention if there is any alternative of inductive isolation to transfer signal proportional to input.

 

Hi lean,
There is the linear/analogue opto-coupler option.
This PDF is one version.
E

 

TI Isolation Amplifiers Here is a list of TI analog isolators. Most they an input voltage of 0 to 2V, or +/-1V or 0.25 or 0.025 and a output of +/-2V. I used a R-R opamp after the isolator.

I looked at the HCNR200 but felt the parts I am using had better temperature numbers and better stability. I needed some speed and it had to work in a very noisy environment.

Here is a page from another company showing a way to use a part.

From TI. I used it this way. With a short across "Vref".