| 摘要 |
PURPOSE:To obtain an operational amplifier which can obtain excellent amplification characteristics up to a limit voltage and can also be composed of a simple circuit. CONSTITUTION:Input resistance R1 is connected to the input side of operational amplifier IC1. Feedback resistance R2 is connected in parallel to amplifier IC1 so as to constitute inversion amplifier BA which can obtain output voltage V2 by being applied with input voltage V1. In parallel to resistance R2, diodes D1 and D2 with anodes connected in common and diodes D3 and D4 with cathodes connected in common are connected. Between the connection point K1 of diodes D1 and D2 and connection point K2 of diodes D3 and D4, Zener diode D3 is so connected that its anode side will be connected to point K1 while the cathode side is connected point K2. Resistance R3 is connected between plus power supply P and point K2, and resistance R4 is between point K1 and minus power supply N. With an input to amplifier IC1 considered to be zero in potential, points K1 and K2 are held at negative and positive levels by setting the values of resistances R3 and R4 in order to flow no current to and from the input terminal of amplifier IC1 via diode D1 and diode D3 respectively. |
