An improved CMOS current differencing transconductance amplifier and its application

This paper proposes a new design of CMOS current differencing transconductance amplifier (CDTA). The proposed design uses a source degenerated differential pair in which biasing current is kept constant and tuning is performed by controlling the value of source degeneration resistance. This scheme provides high transconductance and wide tuning range while the power dissipation remains in the same range as in the existing CDTAs. The workability of the proposed CDTA has been verified by using Mentor Graphics Eldo simulation tool with TSMC CMOS 0.18 μm process parameters. A third order voltage/current mode quadrature sinusoidal oscillator has been designed by using proposed CDTA.