Patent ID: 8791690

Claim:
A semiconductor device having a lateral semiconductor element, the semiconductor device comprising: a semiconductor substrate; a first electrode on a surface of the substrate; a second electrode on the surface of the substrate; an isolation structure located in the substrate to divide the substrate into a first island and a second island, the first and second islands electrically insulated from each other; and a sense resistor (Rs, Rs 1 , Rs 2 ), wherein the lateral semiconductor element includes a main cell located in the first island and a sense cell located in the second island, the main cell causes a first current to flow between the first electrode and the second electrode so that the first current flows in a lateral direction along the surface of the substrate, the first current is detected by detecting a second current flowing though the sense cell, the sense resistor is connected to the sense cell so that a voltage (V 1 , V 2 ) is produced by the second current at a connection point between the sense resistor and a sense cell, the second circuit is detected based on the voltage, and the sense resistor is located at a region that is electrically isolated from the main cell in the sense cell.