History and Progress of the Tow-thomas biquadratic Filter Part II: Otra, CCII, and Dvcc Realizations

The realization of the Tow–Thomas (TT) circuit using the Operational Transresistance Amplifier (OTRA) is reviewed. The circuit employs two OTRA, and all passive elements are floating as the original Tow–Thomas circuit. The Current Conveyor (CCII) TT circuits are reviewed next. The progress in the realization of the TT circuit using CCII is demonstrated clearly by summarizing eight different circuits. One of the circuits has the advantage of very high input impedance using all grounded resistors and capacitors. The Differential Voltage Current Conveyor (DVCC) as the active building block in realizing the TT circuit is also considered. Finally, current mode TT circuits using balanced output CCII are summarized. Top Spice (level 49), simulation results using technology SCN 05 feature size 0.5μm from MOSIS vendor: AGILENT are included to demonstrate the magnitude and phase frequency response of the TT circuits. Additional simulation results for the total power dissipation, total harmonic distortion, intermodulation IM3, input and output referred noise spectral densities are also included for comparison purposes.