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What is the difference between ADC sampling rate and data rate

newbie_hs

Advanced Member level 4
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

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 :

Consult the data sheet.....

Regards, Dana.,

newbie_hs

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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.

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

newbie_hs

newbie_hs

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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 ---

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.

Last edited:

newbie_hs

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