ADS7253: How to caculate the ADC accuracy?

Hi user4411225

If your application is meant to oerform at room temperature then root sum square of typical value of INL, offset error and gain error will give you realistic ADC accuracy calculation at room temp

If application is supposed to work across temp range then take root sum square of max value of  INL, offset error and gain error will give you realistic ADC accuracy calculation across temp

Can you please let me know more about end application

Thanks & Regards

Abhijeet

Hi Abhijeet,

    Thanks for your quick replay. The ADS7253 is used to sample motor phase current in industry servo. I was told to caculate ADC accuracy in full work temp range.  From what I understand, the ADC accuracy  should be caculated by following formula:

      ADC accuracy = TUE_max  /  (2^12) 

    TUE_max = sqrt (sq(Offset Error) + sq(Gain Error) + sq(DNL) + sq(INL))   with thermal drift;

    The resolution of ADS7253 is 12bits, so is the denominator right?

Zhipan

Hi Zhipan

ADC specifications given in datasheet are for full scale range. You need not divide it by 2^12. You need to root sum square of gain error (%), INL (LSB) and oofset error.

If you know input range for your application then you can scale gain error accordingly to get more realistic number

Thanks & Regards

Abhijeet