Semiconductor device and error detector

摘要

In a semiconductor device utilizing a power semiconductor element provided with a main cell and a current sensing cell, a load overcurrent is accurately detected and a short circuit current is rapidly detected. The output of a current sensing cell is connected to an inverting input terminal of an operational amplifier, and a non-inverting input terminal of the operational amplifier is connected to the source of the main cell. A current/voltage conversion circuit configured with the operational amplifier and a sensing resistor converts an output current of the current sensing cell into a sensing voltage. A first error detection circuit compares the sensing voltage with a first reference voltage and outputs an error signal. A 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 source-bias voltage and outputs an error signal.

主权项

1. 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.