[sdiy] Speaking of OTAs/Matched Pairs????

[Jim Patchell]

    The main advantage of a matched pair like the MAT02 is the low
emmiter bulk resistance (Rbe).  I may or may not change my opinion on
that (currently, I am a firm believer in premium matched transistors),
as my belief system has been pretty thoroughly shaken by the realization
that you can buy a bag of 2n3904's and have most of them be withing a
couple of hundred microvolts of each other, I would be willing to
sacrafice the low bulk resistance for the fact that I could have a
matched pair for $0.20! (Bulk resistance is NOT that big of a deal, it
is easily compensated for).

    Arrays like the CA3046 are actaully pretty well matched.  Even on
the speck sheet, typical matching is 500uV (worst case is 5mV).  The
CA3086 does not garentee any matching (it is the same part, just not
tested).

    -Jim

Kevin Peek wrote:

> Are there any advantages by using a matched pair
>  (SSM2010, SC1583, MAT02) IC
> instead of a CA3046, CA3086, CA3080, etc.?
>
> I have always wondered...
>
> Thanks.
> Kevin