| 摘要 |
PURPOSE:To achieve high frequency filter characteristics, by providing a resistor between an inverting input terminal and output terminal and a capacitor between a feedback circuit and the inverting input terminal. CONSTITUTION:When the gain of an amplifier 1 is sufficiently large, since an inverting input terminal can be at imaginary ground potential, no current flows into it. The input current flows to a feedback resistor R7 and an input capacitor C3 by i1, i2 respectively. As a result, the input and output characteristics are those passing through a high frequency filter. In this case, the cut-off frequency is determined by the capacitor C3, resistors R6, R7, R8, and the capacitance of the capacitor C3 can be made small by selecting the value of the resistor R8 suitably. |
