Resistor-Less Single-Purpose or Reconfigurable Biquads Utilizing Single z-Copy Controlled-Gain Voltage Differencing Current Conveyor

摘要

Presented work deals with applications of the single z-copy controlled-gain voltage differencing current conveyor (ZC-CG-VDCC) in single purpose and multifunctional biquadratic voltageand current-mode active resistor-less fllters. Electronically adjustable features of the active device (intrinsic current input resistance Rx, current gain B and transconductance g(m)) are controlled by DC bias current. These mentioned adjustable features allow interesting possibilities of control of the pole frequency and quality factor. Four voltage-mode solutions realizing low-pass, band-pass, high-pass and band-reject flltering solutions were designed together with two current-mode fllters. The current-mode solutions have curious multifunctional capability based on full utilization of electronically controllable parameters of the ZC-CG-VDCC. Two adjustable parameters of the ZC-CG-VDCC (intrinsic current input resistance and transconductance) are used for electronic setting of features of the fllter (pole frequency, quality factor, tuning). Control of the third adjustable parameter (current gain) causes reconnection-less change of the transfer function between iAP (inverting all-pass response) and iBR (inverting band-reject responses). Simulation results in PSPICE and Cadence CDS 6 are used to show characteristics of the proposed circuits.