Autonerdz forums

Hi Nick,

Usually, the true sample rate is less than the requested rate.  As you reduce the time base to the point that the ADC can run at full speed without over filling the buffer, the ADC runs at full speed.   You can't request more than the ADC can do 

The reason that the actual rate reduces, at longer times, is that the ADC speed has to be stepped down when we have longer time bases.  Otherwise, we would over fill the buffer.

That's what the sample rate calculator is for.  If you play with different times, buffer and speeds, you can see the effect.

Here it is:

http://www.autonerdz.com/java/SampleRateCalculator.html

This can be used to compare the performance of different DSOs.