Current sensor, inverter circuit, and semiconductor device having the same

A semiconductor device having a lateral semiconductor element, the semiconductor device comprising:na 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; anda sense resistor (Rs, Rs1, Rs2), whereinthe 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 (V1, V2) 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, andthe sense resistor is located at a region that is electrically isolated from the main cell in the sense cell.

A semiconductor device having a lateral IGBT for controlling supply of an electric current to a load, the semiconductor device comprising:na semiconductor substrate having a first conductivity-type drift layer;a second conductivity-type collector region located in a surface portion of the drift layer and having a longitudinal direction;a second conductivity-type channel layer located in the surface portion of the drift layer and having a straight portion extending parallel to the collector region;an emitter region located in a surface portion of the channel layer and terminated inside the collector region, the emitter region having a straight portion extending in the longitudinal direction;a gate insulating layer located on a Channel region of the channel layer, the channel region being located between the emitter region and the drift layer;a gate electrode located on the gate insulating layer;a first electrode electrically connected to the collector region; and a second electrode electrically connected to the emitter region and the channel layer, whereinthe emitter region is divided to form a main cell and a sense cell, each of which has the lateral IGBT,the lateral IGBT of die main cell is configured to control the supply of the electric current to the load,the lateral IGBT of the sense cell is identical in structure to the lateral IGBT of the main cell and configured as a current detector, andthe main cell is located on each side of the sense cell so that the sense cell is located in the main cell in the longitudinal direction.

A current sensor for detecting an electric current in a current path connected to a load, the current sensor comprising:na power element located in the current path and turned ON and OFF to control the electric current, the electric current flowing through the power element in a forward direction when the power element is turned ON;a freewheeling diode located in the current path and connected in antiparallel with the power element, the electric current flowing through the freewheeling diode in a backward direction when the power element is turned OFF from ON;a first sense cell connected to the power element in such a manner that the electric current flowing through the first sense cell is in proportional to the electric current flowing through the power element;first sense resistor connected in series with the first sense cell;a second sense cell connected to the freewheeling diode in such a manner that the electric current flowing through the second sense cell is in proportional to the electric current flowing through the freewheeling diode; anda second sense resistor connected in series with the second sense cell.