MUX

[Beszedes Arpad]

Hi,
Let me ask another question about SH and MUX circuits:
You never mentioned the refresh rate for the SH caps.
Could some of you recommend an approximate value (msec, usec?) for the
typical configuration described by Mikko below?

Thanks,
  Arpad.

Mikko Helin wrote:
> 
> On Fri, 3 Dec 1999, Guido Goebertus wrote:
> 
> >
> > Can I use standard CMOS 4051/4067 for the MUX? Or is it better to use
> > HCT series? What would be a good choice for the hold caps (type,value)?
> 
> Use the CMOS muxes as you can use them with >5 V voltages, and
> the max. CV out is about 10 V - Vref for 127 MIDI notes in 1/2 steps
> is 127/12 = 10.583333... V, so 12V is a good Vcc for the mux.
> 
> Use 0.1 uF caps with TL082 or TL084 op amps. I think polyester
> caps are OK in S/H's, though there might be better ones, but
> ceramic caps are not recommended (though I don't know why).
> 
> I think at PAiA site (www.paia.com) has schematics of the
> MIDI2VC8 converter, see how the S/H's are done there.
> 
> -Mikko
> 
> >
> > Guido
> > --
> >
> >         \|/
> >        (o o)
> > --oOOO---OOOo--------------/|\-Falcon----------
> >
> > L  |||||||||||||||||||||||||||||||||||||||||||||
> > db -50  -40 -30  -24   -18   -12    -6    0 over
> > R  |||||||||||||||||||||||||||||||||||||||||||||
> >
> > ------Guido Goebertus THD Studio Amsterdam------
> > ---------->Total Harmonic Distortion<-----------
> >
> >

-- 
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*  Arpad Beszedes (research engineer)         *
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*  Hungarian Academy of Sciences              *
*  Attila Jozsef University, Szeged, Hungary  *
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