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cross mob
Level 3
Level 3
I have a question regarding the internal multipexer and I can't find any information on this in the data sheet of the XMC 1302 (even not in XMC4xxx).

How big is the max. error in LSB when scanning different channels (pins) of the ADC?
Assuming all pins are connected to the same voltage, will the reading be exactly the same?

I have a very critical pA metering application and I want to know if I have to use an external analogue multiplexer or
if the internal one fullfills my needs. +- 5 LSB would be good.
My last micro had +- 20 over the different pins and I needed a hardware calibration, which I would like to avoid now.

1 Reply
Not applicable
If the voltage is pretty constant and is not fluctuating quickly over time, I think can safely assume the same voltage applied on all ADC pins would yield the same result? Although I understand from the electrical tables, that the ADC errors especially offset can be different at different pins. And then there is the variation of this across chips. If the application can take this offset error deviation, then no problem I guess?
Also to check out the calibration workaround described on the errata sheets...