S32K3: PTC24 ADC2_S22 acquisition abnormal jumps

[Darrenzhou]

Hello, NXP engineer.

When I used ADC2_S23 for ADC acquisition, I used the same peripheral circuit and the same software code to verify the output voltage value of ADC acquisition. Using PTC25/ADC0_S20, the collected voltage value was basically without abnormal voltage jitter. The collected voltage value showed abnormal jitter.

Figure I: BatVolVal is the ADC0_S20 acquisition voltage without up and down abnormal jitter

Figure 2: After BlindVolVal is the flying line, ADC2_S23 collected the voltage value, and there was abnormal jitter up and down

Figure 3: The same hardware peripheral circuit

2.

* Autosar Version : 4.4.0
* Autosar Revision : ASR_REL_4_4_REV_0000
* Autosar Conf.Variant :
* SW Version : 2.0.2
* Build Version : S32K3_RTD_2_0_2_D2211_ASR_REL_4_4_REV_0000_20221129

Of the dozen ADC channels I've used so far, ADC2_S22 and ADC2_S23is having problems with voltage jumps. Do you have any good suggestions for troubleshooting?

• The ADC0 hardware unit has exactly the same configuration as the ADC2 hardware unit

I look forward to your reply.

Thanks.

[_Leo_]

Hi,

Thank you so much for your interest in our products and for using our community.

The ADC is an analog peripheral with intrinsic linearity errors. The AN13413 explains how to read our spec. There is no calibration magic that will give you an ideal transfer function. It is normal to see a performance difference between ADC channels, they have a different path to the SAR ADC. Some of them are multiplex with digital functions.

Hope it helps you.

Have a nice day!