Patent ID: 7551003

Claim:
A current mirror circuit comprising: a first transistor that has an emitter connected to a power line, an input current of the current mirror circuit flowing through the first transistor; a second transistor that has an emitter connected to the power line and a base connected to a base of the first transistor, an output current of the current mirror circuit flowing through the second transistor; a resistor that has a first end connected between the bases of the first and second transistors and a second end connected to the power line; a third transistor that has an emitter connected to the base of the first transistor and a base connected to a collector of the first transistor, the third transistor supplying a base current to each of the first and second transistors; and a current compensation circuit that adds a compensation current to the input current flowing through the first transistor, wherein the resistor has a predetermined resistance that allows a resistor current flowing through the resistor to be larger than the base current, the compensation current is approximately equal to a value obtained by dividing the resistor current by a current gain (hFE) of the third transistor, the resistance of the resistor allows the resistor current to be approximately equal to the input current flowing through the first transistor or the output current flowing through the second transistor, the current compensation circuit includes a fourth transistor and a fifth transistor connected in series with the fourth transistor, the fourth transistor passes a current equal to the input current or the output current there through, and the compensation current is a base current of the fifth transistor.