How to design a photodiode circuit to get its dark current as output?

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I need to give this pA current to an electrometer circuit so as to convert it to a measurable voltage range.
Also suitable care need to be taken to eliminate the noise.

---------- Post added at 02:11 ---------- Previous post was at 02:07 ----------
Raza said:
Hi,
If you see carefully the data sheet shows shows the DARK CURRENT at the specified diode voltage.
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True.
I need a some 10pA and hence has given a voltage source of 10V
 

 
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Hai

Can you please tell me how to design a compensation circuit for a photodiode using another photodiode so that the noise generated in both these circuits cancel out to give a steady output dark current.
 

Designing a noise cancellation circuit comes next after a perpetual motion machine. By nature, noise is a pure random process, uncorrelated with a second noise signal. So it can hardly be cancelled.
 

For a particular band, noise can be reduced by a log relationship, if many stages are paralelled. This is used in low noise preamplifier stage for microphone. As noise is random but to laws of probability is there. So posibility of noise signal be there in a stage and other stage are different. When many stages are in paralell, the chances of noise in all stages, in phase is less.If it is out of phase, it will cancel.
If many sources of current are in paralell, the noice will be lowered.
 

For a particular band, noise can be reduced by a log relationship, if many stages are paralelled.
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You're referring to amplifier voltage noise and a method to reduce it (possibly increasing current noise at the same time).

The discussion is about noise current of a photodiode, which is mainly pure shot noise (due to the statistical fluctuation of charge carriers). Shot noise is also the lower bound for achievable diode current noise. In other words, there's no means to reduce it below this number.

See: Shot noise - Wikipedia, the free encyclopedia
 

If i had to do such an experiment, i'll arange the system with zero current input and see practically for the noise levels and try to reduce if its too much. If i get stable output for zero input current, only then i'll go for input current source.
I expect its dc current source and taken from dark current of a photo diode. I wonder if shot noise due to photons to be considered as there are no photons in dark.
 

I wonder if shot noise due to photons to be considered as there are no photons in dark.
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The electrons forming the dark current don't care, if they have been released in the junction by photons or other processes. At best, they are completely uncorrelated and their noise density equals the known shot noise numbers. As a worse case, they may be partly correlated, resulting in a noise density above shot noise level.
 

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