| 摘要 |
PURPOSE:To obtain a stable operating point and to convert a fine current into a voltage at high accuracy by applying the converted current to the one input of two transformer impedance amplifying circuit part connected to the two inputs of a differential amplifying circuit part, and applying a reference current to the other input. CONSTITUTION:An output terminal 10b of a second transformer impedance amplifying circuit 10 having the same circuit constitution as a first transformer impedance amplifying circuit part 1 is connected to a input terminals 2a2 of a differential amplifying circuit part 2, and an output terminal 31b of a constant power source 31 is connected to an input terminal 10a of the second transformer impedance amplifying circuit part 10. Further the differential amplifying circuit part 2 differentially amplifies the input voltages applied from two input terminals 2a1 and 2a2, and a differential output is produced from two output terminals 2b1 and 2b2. Thus the stable operating point can be possessed, and the fine current can be converted into the voltage at high accuracy. |
