In Figure 8-1, the high-side power supply (VDD1) for the AMC1301 is derived from the floating power supply of the upper gate driver.

The floating ground reference (GND1) is derived from the end of the shunt resistor that is connected to the negative input of the AMC1301 (INN). If a four-pin shunt is used, the inputs of the AMC1301 are connected to the inner leads and GND1 is connected to the outer lead on the INN-side of the shunt. To minimize offset and improve accuracy, route the ground connection as a separate trace that connects directly to the shunt resistor rather than shorting GND1 to INN directly at the input to the device. See the LayoutLayoutLayout section for more details.