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sampling frequency

betuel
Associate II
Posted on October 11, 2012 at 09:31

Hi everyone!

I'm new to the world of microcontrollers. After some research, I bought my first ARM based Microcontroller; the STM32F4 Discovery.

Now, I have a few questions for the community, hopefully someone can answer me.

how is it calculated the sampling frequency when use multiple channels of the same ADC?

#fc-stm32f4-discovery
2 REPLIES 2
crt2
Associate II
Posted on October 11, 2012 at 09:57

How about you find yourself a datasheet and search for sampling time or sampling frequency?

With my F2 under section 10, subsection 5 (so 10.5 on page 212 in pdf while multiple ADCs is described in lower subsections) I have following statement:

The total conversion time is calculated as follows:

 

Tconv = Sampling time + 12 cycles

Example:

 

With ADCCLK = 38 MHz and sampling time = 3 cycles:

 

Tconv = 3 + 12 = 15 cycles = 0.5 μs with APB2 at 60 MHz

 

I am positive you will find something alike in reference guide for your microcontroller STM32F4xx ( for example http://www.st.com/internet/com/TECHNICAL_RESOURCES/TECHNICAL_LITERATURE/REFERENCE_MANUAL/DM00031020.pdf page 215 to 222 depending on how you'd like to use it)

betuel
Associate II
Posted on October 11, 2012 at 22:09

thanks!