What is the difference between ADC sampling rate and data rate

[newbie_hs]

Dear Team,

May I know the difference between ADC sampling rate and data rate .

If the sampling rate is 125Ksps,can I say data rate is also 125Ksps

 

[danadakk]

Yes, but if ADC multibyte result the data rate scales up (when measured in bytes/sec).
The datasheet will disclose the relationship.

It can also depend if there are special controls to decimate samples :

https://www.analog.com/en/technical-articles/analog-tips-decimation-for-adcs.html

Consult the data sheet.....


Regards, Dana.,

 

[newbie_hs]

Thank you very much for the answer.

If you don't mind could you please explain with an example.

My bad,I did not understand the things from the link you provided.

 

[KlausST]

Hi,

especially for delta sigma ADCs there is a big difference due to oversampling.

It´s not unusual that you have an oversampling rate of 128.
This means
* sampling rate is 128 x data rate.
Example: data rate: 1kSmpls/s, sampling rate 128kSmpls/s

* sampling rate: how often the analog value is converted to a digital value.
* data rate: how often the user/microcontroller gets an ADC value via the digital interface

Just read on delta sigma adc operation.

Klaus

 

[danadakk]

Suppose you have a 12 bits SAR, running at 1 Msps. So its conversion rate is
1 sample every 1 us, or 1,000,000 samples / sec.

Now you have to transfer the data either 1 word (16 word in todays architectures)
or two bytes. So the datarate in words/sec is 1,000,000 words / sec, or 2,000,000
bytes / sec.


Regards, Dana.

--- Updated Sep 18, 2023 ---

Cant edit posts past a certain time.

This :

Now you have to transfer the data either 1 word (16 word in todays architectures)

Should be this :

Now you have to transfer the data either 1 word (16 bit word in todays architectures)

Regards, Dana.