RM57 ADC Calibration

Dmitri Zakharevski59

Other Parts Discussed in Thread: HALCOGEN

Hello,

I am hoping for some clarifying information on ADC Calibration and Offset Error Correction section 22.2.6.1.2 in the RM57 technical reference.

It mentions Computing the error correction value in step 7, but never mentions what computing actually is. I see halcogen just takes the sum of all the values and divides by the number of values (4). Is this the correct calculation?

    /* Compute the Offset error correction value */
    conv_val[4U]=conv_val[0U]+ conv_val[1U] + conv_val[2U] + conv_val[3U];

    conv_val[4U]=(conv_val[4U]/4U);

Thanks!

over 8 years ago

0 Charles Tsai over 8 years ago

TI__Guru**** 191296 points

Hi Dmitriz,

Indeed the TRM is ot specific about how to compute the final offset error correction. The offset error based on different reference voltage are first obtained. But what to do with them? Do we just take the max or the min or simply the mean value? Taking the mean value seems to be the best course of action in my opion. But let me discuss with our ADC expert and get back with you if taking the average as done in HalcoGen is correct.