I want to measure current at the high side of circuit with 0.1 mV accuracy using a 16 bit ADC. for sensing the voltage drop over a 100 mΩ 1% resistor I need to use an op amp which is cheap and easy to implant.
The AD8628 is 3 times cheaper than AD620, so I thought I can get two of AD8628 and measure the voltage with the same accuracy as well. but since I have little to no experience I can't really tell which one is going to give me the result that I'm looking for.
When do we need to choose instrumentation amplifier over differential amplifier and for this specific project which one is more suitable?
Side question; if I match the differential amplifier 1% resistors one by one using DMM, can it be as accurate as 0.1% resistors?