2020-11-25 10:55 PM
Hello,
I am using STM32L471QE.
Please tell me how to calculate CALFACT_S and use it for ADC self calibration.
I confirm that ADC1_CALFACT in CALFACT_S is 0x3A or 0x3B.
I want to know how much [CALFACT_S] affects accuracy.
Please let me know if there is a document that explains ADC self calibration in detail.
I can't understand it to read reference manual.
Thanks.
2020-11-26 05:16 AM
Hello @STaka.3 ,
Welcome to the STM32 Community =)
The ADC self calibration allows to cancel positive and negative offset (+/-64 LSB).
It's an offset calibration, it only corrects the offset error, and this is done automatically by the ADC when you launch a calibration.
Please double check in reference manual RM0351; this should be clear in section "18.4.8 Calibration (ADCAL, ADCALDIF, ADC_CALFACT)".
You can also review the AN2834 Application note How to get the best ADC accuracy in STM32 microcontrollers.
Imen
2020-11-26 04:40 PM
Hello Imen DAHMEN (ST Employee)
Thank you for your answer.
I read manual RM0351.
Add Can you tell us about the following.
How to calculate CALFACT_S ?
VREFINT×〇〇= CALFACT_S?
The sensor output of my product is adjusted at the factory.
And store the AD value of the sensor output in the MCU.
I am worried that the ADC self calibration cause gap of store the AD value.
Shun