High Output Impedance Electronically Tunable Current-mode First-order Allpass Filter with Gain Controllability Based on Current Controlled Current Conveyors

In this paper, a gain controllability current-mode first-order allpass filter employing second generation current controlled current conveyor (CCCII) is presented. The proposed circuit uses three CCCIIs and one grounded capacitor without any external resistors, which is easier for monolithic IC implementation. The gain and phase responses are electronically and independently controlled which is well suited to using for design of the multiphase sinusoidal oscillator. Moreover, the filter possesses high output impedances and thus it enables simple current-mode cascading. The PSPICE simulation results are included, verifying the workability of the proposed allpass filter. The given results agree well with the theoretical anticipation. Supayotin Na Songkla 60