adc 3bit flash ic

mike page · Joined: Sep 26, 2016 Posts: 134 Location: norwich, uk

Hello all,

I'm struggling to find a adc 3bit flash ic. (varying voltage in, parallel 3 bit binary out)
I know I could make it with comparators & xor chips but theres got to be some old adc IC out there that does the job.

any thoughts?

Cheers

okelk · Joined: May 08, 2014 Posts: 71 Location: Vienna

hi mike!

I don't know of any parallel output ADCs with a 3 bit resolution - so just take a 8bit parallel ADC and just ignore the 5 least significant bits!
The ADC0820 is still available and should be quite easy to use...

like you mentioned, taking a bunch ( 7...i think) comparators and a priority encoder like the 74HC148 or CD4532 would certainly an option...might also be cheaper and easier to get than the ADC.

piedwagtail · Posted: Sat Mar 05, 2022 7:20 pm Post subject:

I did a 2 bit switch with a CD4532, TL074 and a DG409 in my 100mm standard.
Passes 4>1 or 1>4 under the control of a 4532 without clocking.
Something nice about unclocked LED indication!

R

okelk · Joined: May 08, 2014 Posts: 71 Location: Vienna

hm...thinking of it, if you want to use a priority encode like the CD4532 to build an ADC, one could also use a LM3914 (dot/bar display driver for level indicators) to drive it...
might also be a cool module on its own with all the lm3914 connections broken out