Optionally adjust the clock of the ADC

[giwonKIM]

Hi I'm KIM from south Korea.

My MCU is "STM32H735ZGT6".

I want to change the clock of ADC1 within the code.

I set up the clock of ADC1 in CUBEMX Clock Configuration about 80Mhz, but I want the clock of ADC1 about 75Mhz.

How can I change the clock?

Thank you.

[Peter BENSCH]

Please share your IOC so that we can take a look at it, because the clock of ADC1 may be a maximum of 50MHz depending on the setting.

Regards
/Peter

[giwonKIM]

I checked that 16bits ADC is up to 50MHz in the datasheet.

But if I use ADC1 or ADC2 as 12bits ADC, can I use it up to 75MHz?

If I want to use 75MHz, is the only way to use ADC3?

[Peter BENSCH · Accepted solution]

The maximum permissible frequency fADC does not refer to the resolution, but to the implementation of ADC1 and ADC2. ADC1/2 are therefore limited to max. 50MHz with ADC_CR_BOOST=11, fADC of ADC3 is unaffected by this and can be set up to 75MHz.

This also answers your second question: a clock frequency higher than 50MHz can only be used with the ADC3.

Regards
/Peter

[giwonKIM]

Thank you. 

I will refer to your advice.