Term for ADC jumping between two discrete values ? Dithering ?

[davey31415]

Hi:

Is there a term for the situation in which a ADC changes between two discrete values?  For instance this is seen when a user zooms into a graph and sees the resolution of the ADC itself creating a saw-tooth like display.

I have heard this referred to as dithering but web searches lead me to colors and searches of NIs forum haven't cleared up exactly what dithering is for me.

Thanks,

David

[Tom_W_[DE]]

Hi David-

The error introduced by discrete A/D converters where the resolution of the A/D results in a "stairstep" effect is commonly referred to as quantization error.  This tutorial has a lot of good info on this and other possible sources of noise/error in a digitized analog signal.

Dithering is a technique where noise is purposefully introduced into a digitized signal with the intention of averaging an oversampled waveform.  The net effect is an effective increase in resolution that results from creating a weighted average of the noise-laden signal of interest.  This tutorial has good info about dithering and other hardware noise reduction techniques.

Hopefully this helps-

[davey31415]

Thanks Tom, I appreciate the thorough reply.  The tutorial links were a great help.

Regards,

David