Kinetis MicrocontrollersのトピックRe: KM34 SAR ADC calibration registers

KM34 SAR ADC calibration registers

jun1 — Fri, 10 Dec 2021 06:01:19 GMT

Hi.

I am trying to omit the automatic calibration at startup by automatically calibrating the KM34's SARADC at the time of board manufacturing, saving the register value in FROM, and writing the value back to the register at reboot. If so, which register should be saved?
Are ADCx_OFS and ADCx_PG okay?
In the explanation of the manual, CLP0, CLP1, CLP2, CLP3, CLP4, CLPS are added to the variable divided by 2, and MSB is set by ADCx_PG, so if you also set the above two register values I thought there was no problem.

Thank you very much.

Re: KM34 SAR ADC calibration registers

diego_charles — Mon, 20 Dec 2021 23:46:43 GMT

Hi @jun1.

You can also consider the plus-side calibration values. ,CLPx registers.

Just note that all the calibration values that you obtain need to be made for every ADC instance. This is mentioned in the recommended calibration procedure of this document 16-bit SAR ADC calibration

Please accept my apologies for the delayed response.

Do not hesitate to let me know if you have any further question.

Diego.

Re: KM34 SAR ADC calibration registers

jun1 — Mon, 24 Jan 2022 03:02:00 GMT

Hi.

"You need to create each ADC instance" means that if you have a CPU with only one SAR-CONVERTER, you can calibrate it with that SAR-CONVERTER, right?
Since the AD input is multiplexed and enters the SAR-CONVERTER, calibration should be done only once for the representative AD input, right?

thank you.

Re: KM34 SAR ADC calibration registers

diego_charles — Mon, 14 Feb 2022 01:39:21 GMT

Hi @jun1

I agree with you.

Diego