Tool/software:
Hi Experts,
My customer is migrating from F280049 to F28076, however, they are seeing a unexpected ADC channel difference when sampled from ADCA and ADCB .
Ax and Bx (Missing the exact channel number, will add this soon) samples same signal with different RC filter. However, A is higher than B by 500 ADC counts.
We've done the following test
1. Connect the two pin together, A was still approximately 100 ADC higher than B (difference reduced).
2. When the two hardware channels were swapped before the RC, the readings remained the same
3. Channel 0 of channel A and channel 12 of channel B are internally connected to the same pin. We attempted to read the same sample in both blocks and changed the trigger source. The results were consistent, with only a difference of approximately 10 ADC.
4. We attempted to change the S/H time between the two samples (these are dummy samples to aoivd channel cross talk) before channel B to 0x26 (320ns) and also to 0x26 on the channel under test, but there was no improvement.
5. We attempted to change the sampling time and trigger source, but there was no improvement.
6. When the same clean voltage (2.5V) was injected externally, the two samples read approximately 3200 ADC, a difference of approximately 30 ADC.
Any idea what's causing the difference?
