To understand better how shunt-based current sensing works, the engineer has to take into account the whole solution with two important parts, on one side the Shunt resistor and on the other the amplification and signal conditioning. Few things are to be taken into account when choosing the shunt resistor. Size: To reduce the power losses and have better thermal performances, a low resistance value is crucial. But the lower the resistance value is, the bigger the shunt resistor is, often beyond the amplifier’s size itself. A typical shunt resistance is 1 or 2 mΩ. Accuracy: The lower the resistor value is, the higher proportion the total error has on the overall signal, and thus the lower the SNR is. So to have a certain accuracy, the resistor value has to stay above a certain threshold to have enough signal to work with. Shunt resistors have an inductance component that will modify the shunts impedance over the frequency. This will impact the accuracy of the solution if not compensated. This needs to be taken into account as it is not always specified in the datasheet.