[ut.ee] Cider Seminar: Friday 11th

dunc@eecg.toronto.edu (Duncan Elliott) (08/05/89)

                Electrical Engineering Computer Group
                         Cider Seminar Series

                        Sigma-Delta Converters

                           Richard Schreier
               Electrical Engineering Electronics Group
                        University of Toronto

         Time: Friday, Aug. 11, 1989, 12:05 --- Place: GB 220

       In academia they are called Sigma-Delta converters.   In  audio
  land,  they are known as oversampled converters.  What they are is a
  nifty way to build both DACs and ADCs and are presently the best bet
  for  achieving  the  18-bit linearity expected by digital audio.  At
  the heart of a sigma-delta converter is a coarse converter, operated
  many  times  faster  than the Nyquist rate, and a very good low-pass
  filter.   The  structure  of  the  converter  is   such   that   the
  quantization noise gets reduced in the band of interest.  One of the
  amazing things about these converters  is  that  this  configuration
  yields  a  low  sensitivity  to analog component errors.  Another is
  that the converter is inherently linear.

       In this talk I will analyze  a  simple  sigma-delta  modulator,
  show  how  to  synthesize,  in theory, a converter of any order, and
  then present some results from my work.

       Questions will be heartily welcomed.  Answers even more so.

  Duncan Elliott, Dept. EE, University of Toronto, Toronto, Canada M5S 1A5
  dunc@eecg.toronto.edu  dunc@eecg.utoronto.ca  uunet!utai!eecg!dunc
  LAT: 43 39' 35.9"N  LON: 79 23' 41.7"W ELEVATION: 349.30          VE3PKD