Hi,
I am trying to sample 3 ADC channels (SE8, SE9, SE15) with sampling frequency 1.6KHz. I have connected a bypass capacitor of 0.1uF on each ADC pin. I am not able to achieve accurate ADC conversion results with DC voltage at ADC input pins. There’s a considerable difference between the expected conversion value and actual conversion result. Also the difference is more for higher DC input voltage on ADC pins.
I have attached the test results for reference.
Development Board used: FRDM K22F
ADC configuration:
Clock used: BUS clock (frequency 60MHz)
Clock Divider: Divided by 4
ADC Calibration: Auto calibrated
Long sampling: Disabled
Continuous conversion: Disabled
Please help in resolving the issue.
Thanks and Best Regards,
Prasanna
Hi Prasanna,
Please refer to this link.How to make ADC counts "stable" in K20/K22 MCU ?
It has some good suggestion. Beside AN4373, AN5250 is also valuable. https://www.nxp.com/docs/en/application-note/AN5250.pdf
Regards,
Jing