TLV6001-Q1: Diff.Amp Available Questions

20 mA × 0.1 Ω = 2 mV, which is smaller than the TLV6001-Q1's input offset error. (The TLV9001-Q1 is cheaper and has a lower offset error.) The voltage drop over Rshunt should be much larger than the error; also consider a larger amplification.

Input voltages near 12 V violate the amplifier's absolute maximum ratings and can damage it.

A difference amplifier is very sensitive to gain resistor tolerances; you should use a current-sense amplifier with matched resistors like the INA180-Q1.

Hello Cho,

I agree with Clemens' comments on the recommendation of the TLV9001-Q1. I would increase the shunt value if possible, since the magnitude of your input voltage is very close to the magnitude of your offset voltage. If this is not possible, you would need to buy a lower offset amplifier.

Additionally, the input voltages would need to remain below the provided supply voltage to the part (in this case 5V). With a .1Ohm shunt resistor that means the maximum allowed current is 50A, which is past the maximum current rating of the FET, so that should not be an issue. However, if the shunt resistor were increased to 1Ohm, your maximum allowed current is 5A. You can additionally protect the input with an external diode. More information on this can be seen here: https://www.ti.com/video/4080379002001 

The relative matching of your resistors is important to the function of this circuit. I would recommend .1% resistors.

Best,
Jerry