AW: Re: Idea for a CV quantizer

Don Tillman don at till.com
Thu Mar 7 07:27:21 CET 1996


Also late.  So sue me...

   From: Haible_Juergen
   Date: Thu, 29 Feb 96 10:55:00 PST

   Yes, I came to something similar last night! Just two sawtooth generators,
   one with approx. 100 times the frequency of the other. It is important
   that the fast one is hard-synced to the slow one to eliminate a
   random offset. 

I'll say!  But sync'ing an oscillator like that is a divide-by-99 just
waiting to happen.  Try this instead:

Oscillator running at roughly 100 KHz drives a divide-by-100 counter
(that would be digital; cmos), which would reset a sawtooth integrator
during its last count.  The comparator compares the input voltage
level with the sawtooth, the output of the comparator goes to a D-Flop
to sync the compare signal to the oscillator, and a second flop to
give us an exactly one-count-long pulse, which gooses the S/H.  The
output will be offset high by about a quantum and a half, but that's
easy to compensate for.

  -- Don





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