| 摘要 |
PURPOSE:To ensure a steady processing of the signal, by extracting the DC component out of the AC signal having the DC component by a filter means and then using it for the bias. CONSTITUTION:While the switch means SW2 selects the input terminal (a), the signal e1 receives the elimination of its AC component by the low-pass filter comprising the resistance R5, the capacitor C4 and others, and is then applied to the input terminal of the differential amplifiers DA1-DAn via the buffer circuit 22 and in the form of the bias. Then when the means SW2 selects the 2nd input terminal (b), the 2nd signal e2 is applied to the other terminal of the amplifiers DA1-DAn via the capacitor C5. |
