ADC home pageIntroductionGoalsWhy digitize?Number RepresentationDigital to AnalogAnalog to DigitalApplicationsLiterature Citations

DAC Speed and Glitches

Choose Subtopic

This section deals with non-idealities and may be skipped on a first reading.

When a DAC is set to a desired output code, it does not instantaneously jump to the desired output current or potential. It changes to the new output potential (or current) over a finite time (the settling time) and may get there with assorted jumps and signal spikes (glitches) rather than transitioning from old to new output values smoothly and monotonically.

There are several causes for such non-idealities:

a) switch capacitance and inductance

b) asynchronous switching

c) finite amplifer speed

For simplicity assume we're using a straight binary, 8 bit DAC. That way, the number representation corresponds to the figures in Ladder Networks and the numbers are small enough to be convenient (0 to 255).

   
 

 

 

 

 

DAC Ladder Networks DAC Coding Schemes DAC Speed and Glitches Scheeline Group Home Page Univ. of Illinois at Urbana-Champaign Home Page Department of Chemistry Home Page Creative Commons License System Homepage University of Illinois Homepage The Camille & Henry Dreyfus Foundation Homepage Home