I need to build a system to monitor several (around ~20) voltages over several days. The ~20 voltages need to be measured differentially. Something which could in theory be accomplishes with 3 of these picologgers.
I was wondering, what is the state of the art way to do something like that?. Do the fine people of Picotech use: a) 8 differential voltages → 8 to 1 Mux → 1 Differential ADC → µController, or b) 8 differential voltages → 8 Differential ADC in parallel → 8 GPIOs in µController ?
Option a) is cheaper but the 8 to 1 Mux needs to be very fast to cycle thourgh 8 channels and not degrade performance. Do they use CMOS Mux? Also it should be a differential mux.What do you guys think?