Log Amp?

Magnus Danielson magda at it.kth.se
Tue Mar 4 19:30:10 CET 1997

>>>>> "P" == POLARIS  <POLARIS at VAX1.Mankato.MSUS.EDU> writes:

 P> I just wondered if anyone (Gene?) noticed the Log amp in the MAT-04
 P> (or was it the MAT-02?) application note.  Would this be suitable for
 P> converting linear keyboard voltages to log VCO voltages?  I think it 
 P> claimed a 10V input voltage range, but this is all from memory, so...

When I looked up the MAT-02 datasheet in my fat PMI databook I found
(as I suspected) that this is basically the same as being used in the
ASM-1 VCO for the exponential cirsuit at the frequency modulation
input. My VCOs (which are using the MAT-02) will sweep around 19-20
octaves with this cursuit.

The basic cursuit is quite well known and it is fairly well
compensated for temperature changes when also using an tempco.

In my opinion is this cursuit well worth the effort to get stable log
or exponetial functions.


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