Betreff: RE: [sdiy] Re: 4049 and 4069

[Czech Martin]

And the year of production is interesting, too.

Surface problems and gate oxide integrity
have improved considerably since 1970 or so.

Perhaps, modern stock CMOS is not useable for noise
because of bad S/N (noise voltage too low compared to hum
etc...).

m.c.

> -----Original Message-----
> From: jhaible at debitel.net [mailto:jhaible at debitel.net]
> Sent: Dienstag, 20. Januar 2004 13:20
> To: Czech Martin
> Cc: synth-diy at dropmix.xs4all.nl
> Subject: RE: Betreff: RE: [sdiy] Re: 4049 and 4069
> 
> 
> > > Are _all_ MOSFETs so bad, noise-wise?
> > 
> > No, the noise corner can be controlled by gate oxide quality and
> > surface quality within some limits. 
> 
> 
> Then it would be interesting to see which brand of 4069
> has the "lowest" noise, compared to others, at least.
> 
> Alot of manufacturers make (or used to make) 4069s.
> Has anybody compared them, noise-wise?
> 
> JH.
> 
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