| 摘要 |
PURPOSE:To ensure a frequency characteristics for a converting circuit itself, by forming a feedback line with a series or parallel circuit of CR at the positive and negative inputs of a differential operational amplifier and using the double terminal impedance which is between a negative input and a common potential point. CONSTITUTION:A differential operational amplifier A has a sufficiently large grain, and the output of the amplifier A is fed back to a positive input and a negative input via a series circuit of a capacitor C2 and a resistor R2 plus a parallel circuit of a capacitor C1 and a resistor R1 respectively. Then a proper resistance R is connected to terminals 2 and 2' each to obtain equivalently the negative L and CR impedance circuits at terminals 1 and 1'. Accordingly the out-of-band characteristics becomes stable at a high frequency since the terminals 1 and 1' approximate gradually to a short circuit. |
