S32K ADC transfer function

[muellermathias]

In the application note AN12217 two different ADC transfer functions are presented:https://www.nxp.com/docs/en/application-note/AN12217.pdf

Unfortunately I could not find any information _which_ is actually implemented in the S32k controllers (in our case S32K144).

Are you able to provide this information?

Thank you in advance!

[muellermathias]

First of all sorry for the late reply (project priorities currently have changed).

I'll try to give an example:

Would I read (in an ideal world) a 1 from the result register if the analog input's voltage reaches

• 0.5 LBS

or only if it reaches

• 1 LSB?

[Robin_Shen]

AN5250 How to Increase the Analog-to-Digital Converter Accuracy in an Application

[Robin_Shen]

Hi muellermathias,

Sorry. We did not offer ADC Actual Transfer Function.(You can not find the curve describing this behavior is the actual transfer function and includes all the errors inherent to the ADC module itself.)

The following ADC specifications can be known from S32K1xx MCU Family - Data Sheet:
Differential Non-Linearity (DNL)
Integral Non-Linearity(INL)
Total Unadjusted Error (TUE)

Best Regards,
Robin
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[muellermathias]

Hello Robin,

I realize that the ideal transfer function cannot be represented by the actual hardware, but surely there must have been a design goal which type of transfer function should be implemented (compensated or uncompensated)?

But maybe I still have an understanding problem there...

Regards,

Mathias

[Robin_Shen]

Hi Mathias,

I'm not sure if I understand what you need, can you show me an example. For the case of 12-bit ADC reference voltage of 5V, does ideal transfer function mean: result=4096*Vin/5 ? 

Best Regards,
Robin