| 摘要 |
PURPOSE:To attain adjustment of sensitivity by adding two transistors (TR) connected to a current source and a circuit power supply with collectors connected in common. CONSTITUTION:The TRs Q5, Q6 connected to the current source CC2 and to the circuit power supply VCC with the collectors connected in common are added to a conventional differential amplifier circuit. The TRs Q5, Q6 are used to change over the current in the current source CC2 and TRs Q3, Q4 change over a current of a current source CC1. In changing the ratio of the current of the current source CC1 to the current of the current source CC2, a quantity (V1-V2) of an input signal required to make the ratio of an emitter current I3 of the TRQ3 to an emitter current I4 of the TRQ4 to a prescribed value is changed. |
