The LMG341xR150 SOURCE pin is also signal ground reference. The signal GND plane should be connected to SOURCE with low impedance kelvin connection. In addition, the return path for the passives associated to the driver (e.g. bypass capacitance) must be connected to the GND plane. In Figure 23, local signal GND planes are located on the second copper layer to act as the return for the local circuitry. The local signal GND planes are isolated from the high-current SOURCE plane except the kelvin connection at the source pin through enough low impedance vias.