S32K ADC Accuracy

[Udhay]

Hello NXP Community,

Seeing voltage measurement accuracy issues on S32K Micro. We have connected 5V Regulated Power Supply to S32K Supply and VREF pins. Unfortunately, 5V Regulator which we have used has 2% tolerance and it may be effecting ADC Measurement accuracy. Any suggestions for compensation of ADC value for better accuracy? Is there any registers within S32K Micro to read VREF value?

[danielmartynek]

Hi @Udhay,

To monitor VREF changes use the internal bandgap ADC channel. The channel
delivers a fixed 1.2 V voltage independently from the reference voltage and the power supply.

danielmartynek_0-1747140918453.png

danielmartynek_1-1747140952870.png

danielmartynek_3-1747141011309.png

The bandgap reference measurement is also a part of the ADC selftest.

danielmartynek_4-1747141126868.png

Refer to the RM, Section 60.3.17.2.4 Self-test analog watchdog for more information about the self-test.

Regards,

Daniel

[Udhay]

Hello Daniel,

Thank you very much for your advise on the ADC Accuracy issue. As you suggested, we will try monitoring the VREF changes using internal bandgap ADC channel. I will let you know incase if there is any issue on implementation of this.

Have a great day! 

Thanks & Best Regards!

N. Udhaya Bhaskara Rao