ADC Accuracy issue

Thiru2483 — Wed, 14 May 2025 18:16:15 GMT

Hi,

I am working with S32k144 and S32k322 MCU in the ADC module.

In s32k144 via tigger source with pdb triggering the adc , and the result observed to be accuracy issue with 40 count

Similarly s32k322 via BCTU , tigger the adc , count accuracy are expected as per the voltage is feed , so accuracy issue compared to s32k144

What this background calibration tigger unit will do exact , why this issue can not be seen in this?

What exact SAR Ip is used ,

Could you please help me out this , as it makes more issue to conclude the exact difference.

Re: ADC Accuracy issue

PavelL — Thu, 15 May 2025 06:19:18 GMT

Hello @Thiru2483 ,

Please check this thread Solved: S32K3 Confusion about ADC accuracy and results - NXP Community . The general description of calibrating capacitive SARs can be found in this thread 16-bit SAR ADC calibration - NXP Community .

If you do all necessary steps during ADC initialization - like calibration - the conversion precision is mainly caused by external components (and VREF, of course) - please refer to AN4373, Cookbook for SAR ADC Measurements - Application note (nxp.com) . Necessary information (CS, CP1, CP2, RSW, RAD, ...) to calculate values of external components can be found in MCU's data sheet.

Best regards,

Pavel

topic ADC Accuracy issue in S32K

ADC Accuracy issue

Re: ADC Accuracy issue