Other Parts Discussed in Thread: INA253, AMC3302, AMC3301
I am designing a current measurement circuit and I want to use one of TI precision current sense amplifiers. My problem is that I need the device to tolerate high common mode voltages (Over 220V) I found some opAmps under "Difference amplifiers" that can tolerate up to 500 Volts but in their datasheets the shunt resistors used in the examples are very large in value (1-10 Ohms) and it's written that the accuracy degrades with decreasing the resistance (because the voltage drop also decreases and the effect of the offset voltage and many other parameters become more dominant). So my question is there a method to solve the accuracy problem when using low resistors such as 5 mOhms or 10 mOhms with High common mode voltage amplifiers? Or is there a method to extend the maximum common mode voltage of precision current sense amplifiers? I found an application note called "Extending Beyond the Max Common-Mode Range of Discrete Current-Sense Amplifiers". The only mentioned solution there was adding resistive voltage divider to reduce the voltage but won't this solution also affect the differential voltage ? Also based on the application note using resistors is risky concerning the accuracy.
Any ideas or solutions?
Thank you very much