Path: utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!cs.utexas.edu!swrinde!emory!wuarchive!decwrl!shelby!eos!jbm
From: jbm@eos.UUCP (Jeffrey Mulligan)
Newsgroups: comp.dsp
Subject: Re: 1 Bit D to A Revisited
Message-ID: <5610@eos.UUCP>
Date: 20 Nov 89 20:38:41 GMT
References: <8911201702.AA03844@en.ecn.purdue.edu>
Organization: NASA Ames Research Center, California
Lines: 23

zawada@EN.ECN.PURDUE.EDU (Paul J Zawada) writes:


>A day or two ago, I heard another one bit D-to-A algorithm from a
>strictly unreliable source.  (A musician friend of mine.)  Since
>1 bit D-to-A was a recent topic, I thought I'd share this one with 
>with the net.  He claims this new revolutionary algorithm uses one
>bit to tell whether the output voltage should be incremented or
>decremented from its current state.

Sounds like a delta modulator (not new).

>Now I'm only an undergrad in EE and I haven't studied dsp much, but
>I cannot see how to actually implement this.  I see a few problems.

Input voltage is tracked on a capacitor.  Capacitor voltage is compared
to input.  Comparator output dumps fixed current on/off the capacitor.

-- 

	Jeff Mulligan (jbm@aurora.arc.nasa.gov)
	NASA/Ames Research Ctr., Mail Stop 239-3, Moffet Field CA, 94035
	(415) 694-3745