[sdiy] improved dynamic range diffpair-vca

[HOSHUYAMA]

Hello Harry,

This one?

http://www.pat2pdf.org/patents/pat3761741.pdf

Sam Hoshuyama

From: harrybissell at copper.net
Date: 2007/04/27 00:23:05
> Checking out the patent (Dolby) and the patents referenced 
> in that patent... it looks a lot like the Moog HPF architecture
> with added transistors for higher linearity....
> 
> They did disclose that 'one' transistor would work...
> 
> The main benefit (imho) from the bipolar method is you do not
> need a FET. That would be a big benefit to someone with a
> monolythic process like Signetics.  Don't need to fabricate
> FETs on the chip.
> 
> It would be a pain to do discretely, imho
> 
> H^) harry
> 
> 
> 
> >>pair with a lot of diodes at the common emitter (Fig. 6).
> >>
> >>  http://www.pat2pdf.org/patents/pat4068139.pdf
> >>
> >>  An OTA with 100% feedback works as a variable resistor.
> >>
> >>It was published in 70's.  So, the Japanese patent application 
> >>can not be patented  ;-)
> >>
> >>Sam Hoshuyama
> >>Saitama, JAPAN
> >>
> >>
> >>From: Aaron Lanterman <lanterma at ece.gatech.edu>
> >>Date: 2007/04/26 03:28:30
> >>> 
> >>> On Thu, 26 Apr 2007, HOSHUYAMA wrote:
> >>> 
> >>> > Actually, what I saw the circuit topology was a patent
> >application (In 
> >>> > Japan, almost all the patent applications becomes public after
> >one and a 
> >>> > half years.) not a filed patent.
> >>> >
> >>> > A couple of years ago, I saw the same structure in a Japanese 
> >>> > electronics book published in 80's. I guess, the structure was
> >not 
> >>> > patented.
> >>> 
> >>> Interesting! Thanks!
> >>> 
> >>> - Aaron
> >>> 
> >>>
> >---------------------------------------------------------------------
> >--------
> >>> 
> >>> Dr. Aaron Lanterman, Asst. Prof.
> >>> and Demetrius T. Paris Junior Prof.  Voice:  404-385-2548
> >>> College of Electri. and Comp. Eng.   Fax:    404-894-8363
> >>> Georgia Institute of Technology      E-mail:
> >lanterma at ece.gatech.edu
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> >>> 
> >>> 
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> 
>