<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class=""><a href="http://hem.bredband.net/bersyn/VCO/8p2ch VC switch_s.pdf" class="">http://hem.bredband.net/bersyn/VCO/8p2ch%20VC%20switch_s.pdf</a><div class=""><br class=""></div><div class=""><br class=""></div><div class="">There’s a 3 bit flash converter here, done in the style of John Simonton. Uses a TL074</div><div class=""><br class=""></div><div class=""><br class=""></div><div class="">Mark</div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><br class=""></div><div class=""><div><br class=""><blockquote type="cite" class=""><div class="">On Nov 28, 2018, at 9:50 PM, David G Dixon <<a href="mailto:dixon@mail.ubc.ca" class="">dixon@mail.ubc.ca</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class=""><blockquote type="cite" class=""><blockquote type="cite" class="">I need three of these<br class="">comparators, and their sole function is to act as a 3-bit AD to <br class="">control some digital switches.<br class=""></blockquote><br class="">But why do you need precise output voltages from the comparators then?<br class=""><br class="">And if you need quad comparators, why not use the good old <br class="">LM339 instead of abusing a TL074 for that purpose?<br class=""></blockquote><br class="">What I want to do is easier (in principle) with an opamp that swings<br class="">positive and negative. I'm using the output state of the comparators to<br class="">provide the threshold voltages to the next comparator in the chain. In this<br class="">way, I can get a reasonably precise 3-bit AD converter. My input CV is -5V<br class="">to +5V, and the AD switches state every 1.25V (-3.75V, -2.50V, -1.25V,<br class="">0.00V, +1.25V, +2.50V, +3.75V). The 2-bit version I used in my 5-channel<br class="">scanner worked perfectly with just divided raw opamp output, but the 3-bit<br class="">version for my 9-channel scanner is a bit more finicky because the levels<br class="">need to be just a bit more precise.<br class=""><br class="">However, I will get it working this afternoon.<br class=""><br class="">_______________________________________________<br class="">Synth-diy mailing list<br class=""><a href="mailto:Synth-diy@synth-diy.org" class="">Synth-diy@synth-diy.org</a><br class="">http://synth-diy.org/mailman/listinfo/synth-diy<br class=""></div></div></blockquote></div><br class=""></div></body></html>