Current differencing transconductance amplifier (CDTA) with high transconductance and its application in filter and oscillator

A new design of current differencing transconductance amplifier (CDTA) has been proposed. In the proposed design of CDTA, two techniques have been combined in order to achieve a high transconductance (gm) while the power dissipation and bandwidth of the proposed CDTA remains in the same range as in the existing CDTA. The first technique is positive feedback which has been used in the conventional PMOS active load of transconductance amplifier (TA) of CDTA. The second technique uses the ‘N’ MOSFETs in parallel in place of conventional differential pair of CDTA where ‘N’ is the number of MOSFETs. The proposed design has been simulated by using Mentor Graphics Eldo simulation tool with 0.18 μm technology parameters. A resistorless sinusoidal oscillator has been proposed by using the new design of CDTA. The performance of proposed CDTA has also been verified by an existing KHN filter.