Hi,
I am conducting a simple Analog-to-Digital conversion test on the MPC5775E and have observed nonlinear behavior in the eQADC conversion results.
Test Description:
- Pins Tested: AN25 and AN32
- Sampling: eQADC0 and eQADC1 sampling at 30 kHz
- Input Signal: A 0.5 V to 4.5 V sawtooth waveform at 0.1 Hz generated using a signal generator
- Setup: AN25 and AN32 are directly connected to the signal generator
Observations:
The conversion results are plotted in the attached graph, alongside an approximation line for reference. The data shows a clear nonlinear deviation from the expected values.
- The maximum conversion error is approximately 70 (in a 14-bit range) when compared to the approximation line, as shown in the second figure.
- This nonlinear behavior persists regardless of using the calibration feature. Notably, the sampled voltages at 25% and 75% of the input signal range appear accurate.
Question:
Could this nonlinear behavior be attributed to a specific hardware or software configuration? Are there any known limitations or additional settings required to address this issue?
Thank you,
