A FAMILY OF SECOND-ORDER ACTIVE RC FILTERS (LPF, HPF, BPF) WITH INDEPENDENT ADJUSTMENT OF THE MAIN PARAMETERS

A bank of circuit design solutions for active RC filters the second order is considered - alow-pass filter, a high-pass filter and band-pass filters, in which independent tuning mainparameters pole frequency, quality factor transmission coefficient isprovided. From these positions, requirements three special transfer functions multipolefrequency-setting circuit, contains two resistors capacitors, are formulated.By choosing coefficients numerator first function, type requiredfilter (LPF, HPF, BPF) implemented. The function chosenso that they affect only frequency pole. It should be noted that, depending on set ofcoefficients polynomial, developed circuits have propertyof lowering or increasing frequency. In this case, choice parametersof third provides necessary attenuation Using theThe introduction describes generalized architecture second-order whichallows implementing an algorithm step-by-step main parameters can usedas basis synthesis many other modifications filters. For correct independentadjustment, following sequence must observed: pole, secondstage adjustment stage scalingfactor. stages class considered, ofthe presented 12 lowpassfilter, confirmed by 14 patents Russian Federation, given.