STM32L433 VREFINT_CAL Value

[RStra]

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

[TDK · Accepted solution]

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

[PR.10]

I was confused by naming mismatch too 🤔. 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). */