Patent ID: 9184729
Filing Date: 2015-11-10
Classification: H03H

Abstract:
1. A reconfigurable Nth-order filter, comprising: a filter stage which includes a second generation current conveyor (CCII) having a y input, an x input, first, second, and third current sense non-inverting outputs, for all stages except a first of said filter stage, second current sense non-inverting output connected to an ungrounded lead of a capacitor portion of a passive circuit having a time constant τ the filter stage further including a first current division network (CDN) having an analog input, an analog output, and a digital control input β the filter stage further including a first digitally controlled current follower (DCCF) having an input, a digital control input α the filter stage further including a second CDN having an analog input, an analog output, and a digital control input β the filter stage further including a second DCCF having an input, a digital control input α a cascade connection of said filter stages, for all stages except a last stage, said passive circuit being formed by a capacitor connected between the y input of the stage and ground, and a resistor connected between the x input of the stage and ground; except for the last stage, said first DCCF outputs of the stages being connected to each other in a feedback loop, said feedback loop connecting the current source b said second DCCF outputs of the stages being connected to each other in a feedforward configuration, the first stage delivering an output signal i wherein the reconfigurable Nth-order filter is defined by a pair of transfer functions characterized by the equations,