[sdiy] 4046 differences?

[Steve Lenham]

Another possible difference might be the amplifier on the signal input - it 
looks the same as one gate of a 4069UB wired up as an analogue amplifier and 
manufacturer-to-manufacturer differences seem to get more pronounced in 
analogue mode.

This is likely to be more of an issue if the signal input is AC-coupled and 
analogue (which it can be - that's why the amp is there) than if it is a 
standard logic signal.

Steve L.


----- Original Message ----- 
From: "Kevin Lightner" <synthfool at synthfool.com>
To: "synthdiy" <synth-diy at dropmix.xs4all.nl>
Sent: Thursday, April 07, 2005 6:13 PM
Subject: Re: [sdiy] 4046 differences?


> >I just looked at a table comparing 39
>>different varieties of 4046, and the Motorola
>>MM74HC4046 variants have an output transition
>>time three times faster than everything else.
>>
>>I remember somethng that was made (surface mount)
>>and the 4046 mattered, but I can't remember why.
>>
>>paul perry (Frostwave analog fx) Melbourne Australia
>
>
> Thanks to all that replied.
> I wouldn't mind this chart above either :)
>
> Here's something interesting that I found on someone's website via Google:
>
>>>Take care about which 4046 chips you use for U1 and U3. The
>>>Phillips 74HCT4046 chips (formerly sold by Radio Shack) are fine.
>>>So are CD74HC4046 chips made by Harris or T.I. Do not use chips
>>>made by Fairchild and do not use CD4046 chips; both have a
>>>different design and will not work in this circuit.
>
>
> Keep in mind that I'm speaking about the same chips, but from
> different manufacturers.
> MC14046's from Motorola seem to be different than CD4046's from
> Fairchild, for example.
>
> -- 
> Regards,
> Kevin Lightner
>
> Myself: http://www.synthfool.com
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