A new CMOS ZC-CDTA realization and its filter applications

Abstract

The Z copy current differencing transconductance amplifier (ZC-CDTA) is a new current-mode active element that was introduced recently. ZC-CDTA is improved from the current differencing transconductance amplifier (CDTA) and has increased its universality. In the current study, a CMOS implementation of ZC-CDTA is proposed. The first stage of ZC-CDTA consists of a current differencing unit. The output stage consists of a dual output transconductance amplifier. Furthermore, a third-generation current conveyor is used to copy the Z terminal current instead of a classical current mirror. A fourth-order filter application employing ZC-CDTAs is given and simulation results are added. The ZC-CDTA-based filter is designed starting from a previous filter structure that employed conventional CDTAs. Thanks to the Z copy, the high-pass filter output problem is solved for the conventional CDTA filter structure. AMS 0.18m CMOS parameters are used for the simulations.