| 摘要 |
PROBLEM TO BE SOLVED: To obtain a differential input circuit by which the generation voltage of a sensor can be fetched as an output voltage as it is by providing a current source which is connected to an input terminal and by which a current equal to a current flowing in a resistor is made to flow into the side of the input terminal. SOLUTION: A second current source 5R is connected to a signal line 55. A reference voltage line 32 is connected to the second current source 58. By a first current source 34, a current I1 which flows through the inside of a differential input circuit during its operation becomes a value which is identical to a current I6 which flows to a second transistor 70. In the same manner, by the second current source 58, a current I2 which flows through the inside becomes a value which is identical to a current I5 which flows through a first transistor 44. Thereby, it is possible to realize the differential input circuit which has an apparently infinite input impedance and in which voltages VIN1, VIN2 appearing at a first input terminal and a second input terminal can be changed to mutually opposite phases while a proper reference voltage is used as the center. |
