STM32H723ZG max ADC data transfer rate

[beauwilmink]

Hi,

I'm confused about the maximum data transfer of the STM32H723ZG. The overview says:

• 2×16-bit ADC, up to 3.6 MSPS in 16-bit: up to 18 channels and 7.2 MSPS in double-interleaved mode

Then the 'AN5354 -  Getting started with the STM32H7 Series MCU 16-bit ADC' also mentions these data rates for the H7 series but not specifically the STM32H723ZG. This application note also specifies a huge discrepancy between different packages and rates:

Then, assuming these numbers correspond to the direct channels, what are the data rates for the fast or even slow channels? 

Also, CubeMX doesn't clearly indicate which ADC channels are direct, fast or slow, maybe this is a functionality that could be added?

[AScha.3 · Accepted solution]

Hi,

>confused about the maximum data transfer of the STM32H7

End of confusion : maximum data rate is always same, as in ds : up to 3.6 MSPS in 16-bit ...etc.

The problem is: what will be the real/effective resolution or precision you get then ?

And THIS depends on many factors : setting of ADC sampling time, input impedance at pin, length of line/wire to this point (so also size and type of its package ), internal resistance of the analog path + switches to that pin ("slow" or fast etc.),

noise on Vref , noise on chip GND /AVSS , layout of board and routing, activity of cpu and next pins (stray in spikes), ...etc.

+

>CubeMX doesn't clearly indicate which ADC channels are direct

Right, you have to look in rm for your cpu, to see this in detail:

CubeMX cannot know, what you want to connect and what real resolution will be possible then,

vs what you expect. It shows just, what can be used/connected to a pin .

 Whether this makes sense for the intended design , or not, is your decision. :)