A New Trans-admittance-Mode Biquad Filter Suitable for Low Voltage Operation

The trans-admittance-mode (TAM) might act as a transforming bridge for voltage-mode to current-mode conversion. In this study a new low voltage operated electronically tunable TAM biquad filter structure realizing all the seven standard filtering functions namely; low-pass (LP), band-pass (BP), high-pass (HP), regular-notch (RN), low-pass-notch (LPN), high-pass-notch (HPN) and all-pass (AP) from the same configuration through appropriate selection of voltage inputs is presented. The proposed circuit structure comprises of three current conveyor trans-conductance amplifiers (CCTAs). Moreover, the new biquad filter structure still enjoys (i) realizations neither require inverted nor scaled voltage input(s), (ii) the employment of two grounded capacitors (Ideal for IC implementation and attractive for absorbing shunt parasitic capacitances), (iii) the pole frequency can be tuned electronically, (iv) possesses low incremental active and passive sensitivity performance and useful in low-voltage low-power applications. PSPICE simulation results using 0.25μm TSMC CMOS parameters verify the theoretical analysis.