Tool/software:
Hello,
I'm using the TMDSCNCD28379D controlCARD version R1.3 within the docking station rev F and encountering unexpected ADC behavior.
Issue Description:
When I apply 3.3V from the board to ADC-B1 (HSEC pin 14), I correctly read 4095 in the ADC buffer. However, I notice the following on ADC-B2 (HSEC pin 18):
- When ADC-B2 is floating, I read around 650 LSB.
- When ADC-B2 is grounded, the reading drops to 70 LSB, which still seems high.
If I remove the 3.3V from ADC-B1, all ADC readings drop to zero as expected.
My configuration:
- ADC-B, single-ended mode, 12-bit resolution.
- Conversion time: 75 ns.
- Sampling frequency: 19.8 kHz.
I didn't expect this behavior with such high values. My expectation was a noise level of around 3 to 5 LSB, not 650 LSB.
Questions:
- Has anyone experienced similar behavior with this controlCARD?
- Could this result from coupling between channels, an issue with grounding, or something else in the ADC configuration?
- Are there specific steps I should take to debug this further?
Here a screenshot of my readings in the variable inspection:
Thanks in advance.
