2mA - 30mA Current sensor using Instrumentation or Current sense amplifier

Using Arduino Project Guidance
#1

Hi guys,

I am going to build a simple circuit for current measurement. I am facing a problem in measuring a current range from 2mA- 30mA for my project. FYI, my system operates at 3.5- 5V. Any recommendation for the selection of components(both amplifier & shunt resistor)?

Please see the file attached.

Regards,
Jaysee

clip_image001_20080309140125.jpg

#2

Do a Google search for "high side current sense amplifier", then read the datasheets.

#3
#4

I have decided to use:

as my current sense amplifier. But for the current sensing resistance, I am not too sure what is the value to be used in my application ( Measuring 2mA -30mA )..

Can anyone please share their knowledge? Thanks.

Following link is the available range of current sensing resistance:

https://www.digikey.com/Web%20Export/Supplier%20Content/tt-electronics-welwyn-985/pdf/welwyn-an-current-sense-resistors.pdf?redirected=1

Thank you very much!

#5

Decide what you want the output voltage to be at full scale.
Divide that by the gain to give the required voltage drop across the resistor (there are 3 versions of the device with different gains).
Calculate the resistor value that gives the required voltage drop at 30mA.

#6