For isolated analog input, we can have the analog signal or the digital signal to be the point of isolation, meaning that, we can either use a linear opto (at the input of the ADC) or a digital opto (at the output of the ADC).
The pro and con of the two methods that I could think of would be:
1. Linear opto is more expensive, and more difficult to design for precision application.
2. For isolation at the digital point (i.e. the ADC digital output is isolated), the ADC will be damaged in case of surge.
What other pros and cons that you know? Please share your experience. Thanks!