| 摘要 |
<p>PURPOSE: To eliminate the necessity of a differential filter stage and annexed overlapped parts by subtracting an output signal filtered from a 1st circuit and impressed to a 1st input from an input signal impressed to a 2nd input and supplying a differential output signal to an output. CONSTITUTION: In response to differential input signals VIN impressed to a bipolar filter stage 32, the filter stage 32 is tuned with natural frequencyω1 in addition to an attenuation constantζ1. Output signals from the stage 32 are processed through bipolar filter stages 34, 36 and respectively tuned with attenuation constantsζ2,ζ3 and natural frequenciesω2,ω3. Output signals from the stage 36 are processed through a real polar filter stage 38, tuned with frequencyωn and outputted as differential output signals Vout. Although differential input signals to the stage 38 are impressed to differential amplifiers 40, 42 as non-inversion inputs, the differential output signals from the stage 38 are impressed to the amplifiers 40, 42 as inversion inputs and single end outputs from the amplifiers 40, 42 are outputted as differential output signals DIFF.</p> |
