[sdiy] Issue with CD4024 Ripple Counter

Ben Bradley ben.pi.bradley at gmail.com
Sat Sep 18 00:09:21 CEST 2021


How old are these chips (the MC14xxx as well as the CA)? When did you buy
them and from whom? Who's the manufacturer and what's the datecode?

It's conceivable chips could go bad over several decades, either the
processes weren't that great or the encapsulation wasn't good enough. I've
also heard of electron migration, but that only happens while a chip is
powered up, and wouldn't apply to new or NOS chips.

I'm looking at the TI datasheet, and it's scanned (!):
https://www.ti.com/lit/ds/symlink/cd4024b.pdf
It does have some non-scanned text: " Data sheet acquired from Harris
Semiconductor"
So did Harris buy RCA's CMOS line, then TI got it from Harris?

I see this as a point of frustration, but enquiring minds want to know what
happened.


On Fri, Sep 17, 2021 at 4:27 PM David G Dixon via Synth-diy <
synth-diy at synth-diy.org> wrote:

> I'm tempted to dig those shitty chips out of the trash and mail them to
> you, to see if you fare any better, given that I'm such a noob (with 13
> years of experience designing millions of dollars worth of successful synth
> modules).
>
>
> ------------------------------
> *From:* bbob [mailto:fluxmonk at gmail.com]
> *Sent:* Friday, September 17, 2021 12:10 PM
> *To:* David G Dixon
> *Cc:* synth-diy mailing list
> *Subject:* Re: [sdiy] Issue with CD4024 Ripple Counter
>
> [*CAUTION:* Non-UBC Email]
> lots of designers have used CD4000 series CMOS in SDIY circuits
> successfully.  they have their place if used properly, and their
> limitations (like every technology).  would be a shame if a newcomer were
> to be scared off of perfectly good parts just because you couldn't get it
> to work in your application.
>
> bbob drake
>
> On Fri, Sep 17, 2021 at 2:52 PM David G Dixon via Synth-diy <
> synth-diy at synth-diy.org> wrote:
>
>> So, I went to the lab and set up a little breadboard.  I put 4024 on it,
>> used my +15V and 0V rails to power it (yes, I decoupled with 104), and I
>> also set up a TL072 as a comparator driven by a triangle-wave LFO.  I sent
>> the output of the comparator through a diode to have it go just between 0V
>> and +15V.  I tried clocking two CD4024BEs, two CD4024BCNs, and one
>> MC14024BCP.  The CD4024BCNs didn't even work.  The CD4024BEs gave me some
>> really hashy looking outputs.  The MC14024BCP worked perfectly.  Then I
>> tested them in an ASR, with similar results.
>>
>> So, I threw all of the CD4024s into the trash.  Unfortunately, I only have
>> one MC14024B.  I'm going to buy more, cuz they work well, without any
>> issues.
>>
>> Lesson learned, I guess.  I'm just not sure what the lesson is, other than
>> "don't use CD4XXX chips" or at least ones with edge-driven inputs.
>> Argghh!!!  Why can't this stuff just work?  It's a miracle that we aren't
>> still living in caves, wearing skins and hunting sabre-tooth tigers with
>> sticks.
>>
>> _______________________________________________
>> Synth-diy mailing list
>> Synth-diy at synth-diy.org
>> http://synth-diy.org/mailman/listinfo/synth-diy
>> Selling or trading? Use marketplace at synth-diy.org
>>
> _______________________________________________
> Synth-diy mailing list
> Synth-diy at synth-diy.org
> http://synth-diy.org/mailman/listinfo/synth-diy
> Selling or trading? Use marketplace at synth-diy.org
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://synth-diy.org/pipermail/synth-diy/attachments/20210917/093d6f03/attachment.htm>


More information about the Synth-diy mailing list