Low Pass Filter of the Sallen-Key Family with Main Parameters' Independent Adjustment

The new low pass filter's circuit (LPF) of the Sallen-Key family of the second order is considered, in which an main parameters' independent adjustment by digital-controlled resistors is realized: pole frequency, the quality factor and the scale transfer coefficient. The basic mathematical equations for the transfer function of the low pass filter are obtained. The comparison of the parameters of the known and proposed circuits is given. The results of LPF modeling in the Micro-Cap SPICE simulator are discussed.