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Visitor II
May 4, 2020
Solved

STM32L433 VREFINT_CAL Value

  • May 4, 2020
  • 2 replies
  • 2171 views

Hello,

I'm trying to work with the ADC of the STM32L433 microcontroller. The Reference manual (RM0394) on page 448 it says :

The following formula gives the actual VDDA voltage supplying the device:

VDDA = 3.0 V x VREFINT_CAL / VREFINT_DATA

Where can I found the VREFINT_CAL value, I'm not able to find the address on the RM ?

Thank you

Riccardo

    This topic has been closed for replies.
    Best answer by TDK

    It's in the datasheet. Note that it's called VREFINT here instead of VREFINT_CAL.

    0693W000000Wr32QAC.png

    2 replies

    TDKAnswer
    Super User
    May 4, 2020

    It's in the datasheet. Note that it's called VREFINT here instead of VREFINT_CAL.

    0693W000000Wr32QAC.png

    Graduate II
    February 29, 2024

    I was confused by naming mismatch too :thinking_face:. For people from future, there are actually a built in macros for that which do have matching names. So the code can stay correct when you change mcu variant. in *adc.h

     

     

    /* ADC internal channels related definitions */
    /* Internal voltage reference VrefInt */
    #define VREFINT_CAL_ADDR ((uint16_t*) (0x1FFF75AAUL)) /* Internal voltage reference, address of
     parameter VREFINT_CAL: VrefInt ADC raw data acquired at temperature 30 DegC
     (tolerance: +-5 DegC), Vref+ = 3.0 V (tolerance: +-10 mV). */
    #define VREFINT_CAL_VREF ( 3000UL) /* Analog voltage reference (Vref+) value
     with which VrefInt has been calibrated in production
     (tolerance: +-10 mV) (unit: mV). */