摘要 |
A combined recursive/transverse filter has an input element (E) and several integrating elements (I1 to In). The output signals of the integrating elements (I) to (In) are supplied to the inputs of two adders, each formed of individual adder elements AA and AB. In addition, each adder has a load element (L1 or L2). The output of the adding elements of each adder are combined and connected to the output of a corresponding load element (L1, L2). The output signal of each adder is supplied to the non-inverting input (-) of the respective load element. All elements are designed as voltage-controlled current sources connected to a downstream device which calculates the arithmetic difference between the output currents. Such a transconductance amplifier may also form a cell, and an amplifier may be formed of a combination of several parallel connected cells. The individual cells may be switched on and off by binary signals, making it possible to obtain programmable filtering structures. |