| 摘要 |
<p>A plurality of low-pass filters (2<SUB>-1</SUB>, 2<SUB>-2</SUB>, 2<SUB>-3</SUB>) are cascaded to the post-stage of an OTA (1) and a plurality of high-pass notch filters (3<SUB>-1</SUB>, 3<SUB>-2</SUB>, 3<SUB>-3</SUB>) are cascaded further to the post-stage thereof so that a high-pass filter having a high Q is not connected to the output of the OTA (1) having a high output impedance and a capacitor having a low capacitance is not connected with the output of the OTA (1) thus preventing multifeedback and avoiding such problems as the zero point of the notch filter (BEF) deviates from a design value or oscillation takes place.</p> |
