Patent ID: 8803508

Claim:
A semiconductor device comprising: a power semiconductor element including a main cell and a current sensing cell, wherein a drain of the main cell and a drain of the current sensing cell are connected together, and a current in the main cell is detected based on an output current in the current sensing cell; an error detector including a first error detection circuit and a second error detection circuit, the first error detection circuit including an operational amplifier, wherein a source of the current sensing cell is connected to an inverting input terminal of the operational amplifier, and a source of the main cell is connected to a non-inverting input terminal of the operational amplifier; the first error detection circuit further compares a sensing voltage, which is converted from the output current of the current sensing cell by a current/voltage conversion circuit configured with the operational amplifier and a sensing resistor, with a first reference voltage and outputs a first error signal; and the second error detection circuit compares a voltage at the inverting input terminal of the operational amplifier with a second reference voltage set to be higher than a voltage at the non-inverting input terminal of the operational amplifier and outputs a second error signal.