The voltage drop across the power path impedance and the ground path impedance due to load transient currents. Impedance is unavoidable in any electrical path on a PCB, be it the complete power plane or the power leads. For multi-layer boards, a complete power plane and ground plane are usually provided. The output of the regulated power supply is first connected to the power plane, and the supply current flows through the power plane and reaches the load power pin. The ground path is similar to the power path, except that the current path becomes the ground plane.