Looking for current sense amplifier 1 uA to 10 mA.

Medha,

A design like this will be challenging. You are asking to measure a resolution range that is 10000:1 from low end to top end, and have some level of precision across the totality of the range. There are a few issues that make this difficult:

- To be able to successfully measure 10mA at the top end of the full scale range, a sense resistor needs to be chosen such that you don't saturate the amplifier. For example, if the amplifier you intend to use has a gain of 50 and you plan to supply it with 5V, this means the maximum input voltage you could have at the pins is 100mV. While a resistor can easily be chosen for the 10mA range to satisfy this, the voltage that will be generated by the lower end of the system will be almost negligible. 

- Because of the above, the voltage generated at the low end will be dominated by the offset voltage of whatever amplifier you choose to use, introducing massive amounts of error at the low end of the measurement. 

Typically, for a system that needs such a wide FSR, you would need to figure out an analog front end that will shape the voltage heading into the amplifier, or arrange a set of amplifiers so that they handle different parts of the full scale range. 

I would recommend looking at the INA190. For the lower current measurements, you may also have a look at our instrumentation amplifier products.