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Log Amp for High Power Optics

Question asked by ARodgers on Feb 18, 2015
Latest reply on Feb 24, 2015 by ARodgers

I am currently using the ADL5303 for optical power measurements in the range of -70 to +6 dBm.  I am using a photodiode with a responsivity of approximately 0.9A/W, and this works well.  I now need to make power measurements in the -30 to +26 dBm range, and I have sourced a photodiode with a responsivity of 0.113A/W.  What this means is that the photodiode current could get as high as 45 mA, which doesn't seem to be covered by any log amps offered by Analog Devices.  I also tried looking at current mirrors, but again the current is too high.  Does anyone have any suggestions or recommendations?  Thanks.