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STM32H747 ADC resistance R_ADC missing from datasheet

Associate II


I'm working on a project where I need ADC readouts with very little jitter and therefor use synchronous mode. As I have several side conditions on the clock domains, I can't choose the ADC clock freely.

Hence, I'm trying to evaluate if for a given ADC clock, a readout at a specific precision is possible. I'm also interested in the maximum analog source resistance for a given scenario.

To do so, I'm using Application Note 2834 (How to get the best ADC accuracy), specifically the formula of section 3.2.6 (Analog source resistance calculation). To properly use the formula I need R_ADC, the resistance of the ADC. Sadly, the datasheet of the STM32H747xI/G does not provide this information. Even worse, if I try to estimate R_ADC from the max R_AIN values, the results are inconsistent...

TL;DR: I need R_ADC of the STM32H747xI/G and datasheet values for R_AIN are inconsistent with AN2834.

Thank you!

Note: this question is closely related to this unanswered question: