This is a logarithmic amplifier circuit based on National operational amplifier LM11C. Unusual frequency compensation provides this logarithmic converter a 100 us time continual from 1 mA down to 100 uA, escalating from 200 us to 200 ms from 10 nA to 10 pA. Optional bias electric current compensation can give 10 pA resolution from -55 ? to 100 ?, Scale aspect is 1 V/decade and temperature compensated.
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