| 摘要 |
PURPOSE: To freely change a limiter level in a limiter circuit for limiting the output signal level of an amplifier circuit. CONSTITUTION: The amplifier circuit 11 is constituted of an invertible amplifier circuit 21 composed of an amplifier A1 , a resistor Ra and the resistor Rb and this limiter circuit 22. An input terminal TIN2 is set at a fixed potential VIN2 and an input voltage VIN1 for which the potential VIN2 is a reference potential is supplied to the input terminal TIN1 . The negative side limiting circuit 23 of the limiter circuit 22 is constituted of a first limiter level setting circuit 25 composed of a constant current source 31, a transistor Q1 and the resistor R1 and a current absorbing circuit 26 constituted of the transistor Q2 . A positive side limiting circuit 24 is constituted of a second limiter level setting circuit 27 composed of the constant current source 32, the transistor Q3 and the resistor R2 and a current inserting circuit 28 constituted of the transistor Q4 . |
