Patent ID: 9712149
Date: 2017-07-18
CPC Classifications: H03K

Claim:
1. A semiconductor device comprising: a power transistor; a sense transistor having a gate connected to a gate of the power transistor and a collector or drain connected to a collector or drain of the power transistor; a first operational amplifier having a first input terminal connected to an emitter or source of the sense transistor and a second input terminal connected to an emitter or source of the power transistor; a resistor element having one end connected to the emitter or source of the sense transistor and another end connected to a first node; and an adjustment transistor placed between the first node and a low-voltage power supply and having a base or gate supplied with an output of the first operational amplifier, wherein the first operational amplifier adjusts a current flowing through the adjustment transistor so that a voltage of the emitter or source of the power transistor and a voltage of the emitter or source of the sense transistor are substantially the same, and wherein the adjustment transistor is placed in a first semiconductor chip and the first operational amplifier is placed in a second semiconductor chip which is different from the first semiconductor chip.