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Current to voltage converter

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yes..that is why I asked you to help me!!!!!
But if you do not have any idea, it is fine.
Thank You so much. :)
 

strange project, my friend
... with requirements as clear as mud and no context.:roll:
I guess your scale is too big.... 10pA -10mA
A logarithmic scale may be more useful. The current could be passed through a diode, and the voltage drop across the diode sensed with a suitable opamp. CMOS opamps are available with bias currents less than 1pA.
 

According to me, I have provided you all the information, tell me what you don't understand.
I am using log graph.
Thanking You.
 

You may try looking up logarithmic amplifiers. They are expensive though but they may handle the wide current range better
 

Can you help me in designing a circuit for shorter range?
Like 10pA-20nA.
Thank You.
 

Can you help me in designing a circuit for shorter range?
Like 10pA-20nA.
It's easy. Refer to the circuit from post #10, calculate a suitable feedback resistor value (500 Meg), change 741 against an "electrometer" OP with sub pA input current (e.g. OPA129) and you're done.

But does a linear, single range I/V converter solve the problem? It possibly does for the restricted 1:2000 range but surely can't for the original 1:10e9 range.
There are at least three possibly solutions:
- multiple ranges with manual selection
- autoranging
- non-linear characteristic like the said log curve

It looks you didn't yet think about a full project specification. I wonder if others (e.g. the project supervisor) did.
 
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