Vertical resolution of oscilloscope

Hi experts,

How is the oscilloscope vertical screen range related to ADC resolution? For example if scope ADC is 8 bit how does it translate to the screen when range is set to 5V/div or 10V/div. Is there a programmable amplifier at the input of the ADC?

Thanks and regards, Pawan

Hi Pawan,
Using your example range; if you had 5V/div and 10 divisions, the vertical range would be 50V.
With the 8 bits, there would be 2^8= 256 voltage levels represented across 50V. 50 Volts/256 levels = 0.1953125 V per level.
The scope may use some bits to detect clipping on the signal though.

As for the programmable amplifier, what scope are you using/referring to?

Best,
Iris Xu
 

Hi Iris,
Thank you for the quick reply! So if I had the range set at 10V/division then my LSB would only be 0.390625V.

Lets say I am using a 10x probe and measuring a 10V signal. Assuming the full-scale input range of the ADC is 3V. If the ADC is 8 bit then LSB would be 0.0117V. Then how would the measurement resolution change on the input signal when the vertical resolution of the screen is changed.

Best regards,
Pawan