Notch filter on differential difference operational amplifier

A new notch filter (NF) circuit based on a single differential difference operational amplifier (DDA) has been developed and studied, which is characterized by reduced current consumption in the static mode. Equations are obtained for the transfer functions and parameters of the NF, which includes a low-pass filter and a Sallen-Key high-pass filter, the signals of which are summed by the DDA. Computer modeling of the NF in CAD Micro-Cap was performed.