How to detect an voltage drift at ADC Varef?

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User17279
Level 1
Level 1
How I can detect a voltage drift on the ADC Reference Voltages, somebody has an idea?
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User17382
Level 1
Level 1
Hi,
if your are talking about AURIX first generation. TC22x, TC23x, TC26x, TC27x and TC29x the following can be done.
On TC23x the bandgap voltage is accessible internally by using the "ALIAS" feature of the ADC. This bandgap voltage can be measured and compared against an expected value e.g.*
In fact the bandgap voltage can be expected to be in the 2,4V +/- 1,5%
*
If the measured value is different to the 2,4V (with some margin for sure. e.g. +/- 3%) the Varef seems to drift.
Other options are to read in the 1.3V core voltage or 3.3V supply voltage in TC26x,TC27x,TC29x derivatives where the bandgap is not accessible.
Of course an external high precision analoge signal which can be measured could be used as plausibility check for the Varef too.

BR
cosmo01

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