Abstract: A semiconductor device obtains high current ratio accuracy by eliminating an influence of plasma charging using a MOS-type transistor in which a channel region is isolated and separated from a semiconductor substrate. In a current mirror circuit in which both of a well of a NMOS-type transistor that generates a bias and a well of a NMOS-type transistor that receives the bias are formed insulated and separated from a semiconductor substrate, a connection circuit is connected between gate electrodes and wells of NMOS-type transistors without through the semiconductor substrate, and the connection circuit makes the gate electrodes and the wells in an electrically short-circuited state during manufacturing of the current mirror circuit, and makes the gate electrodes and the wells in a disconnected state in at least one direction during a mounting operation.

Abstract: The purpose of the present invention is to provide an engine control system that is capable of promoting mixing of fuel and air during exhaust gas recirculation, thereby suppressing combustion fluctuation of a gasoline engine, such that efficiency and exhaust gas purification can be simultaneously achieved. The engine control system controls an engine and is equipped with an injection device for injecting fuel directly into a cylinder and a recirculation device for recirculating exhaust gas to the intake side.