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I am trying to understand the derivation of a logarithmic amplifier as shown in the figure attached.
The diode has a non linear characteristics represented by V=ClnI,where C is a constant.
Then since the current through the feed back loop is the same as the current through the input resistance and the potential difference across the diode is Vout,we have
Vout=Cln(Vin/R)=Kln(Vin) where R is input resistance.
What I cant understand is the step in bold,what mathematical rule is used between the two equations?
Thank you in advanced .
The diode has a non linear characteristics represented by V=ClnI,where C is a constant.
Then since the current through the feed back loop is the same as the current through the input resistance and the potential difference across the diode is Vout,we have
Vout=Cln(Vin/R)=Kln(Vin) where R is input resistance.
What I cant understand is the step in bold,what mathematical rule is used between the two equations?
Thank you in advanced .
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