| 摘要 |
PURPOSE:To obtain the same electric current as an input current at an output terminal by compensating at least base currents of the 1st and 2nd transistors with an inverted current proportional to the base current of the transistor. CONSTITUTION:A base current ib4 which is almost the same as the base current ib3 of a transistor Q3 flows to the base of a transistor Q4 and is inputted to an inverted current generation circuit 2. The electric current which tends to flow to an input terminal IIN through the diode connecting section of a transistor Q1 is equal to an electric current which is three times as large as the base current of the transistor Q1. Moreover, since an electric current which is three time as large as the base current ib1 is forcibly made to flow to the collector of the transistor Q6 of the circuit 2, no base current flows to the input terminal IIN. Therefore, an electric current i2 which is equal to the electric current inputted to the input terminal IIN is obtained from an output terminal IOUT and the potential difference between the input terminal IIN and a supply voltage +VCC becomes the forward voltage across the base and emitter of the transistor Q1 only when a voltage drop caused by a resistance R1 is ignored. |
