Universal Tunable Current-Mode Biquad Employing Distributed Feedback Structure with MO-CCCII

One possible application of the multiple-output electronically-tunable active building block as a universal filter with distributed feedback structure is presented. The suggested structure is less conventional than the well-known state-variable Kerwin-Huelsman-Newcomb but allows the same filter configurations with the similar properties. The major current-mode design approach disadvantage, ie, the necessity of multiple current outputs, is demonstrated. To date even a rather big line of the commercially available devices do not solve this problem. Some features of the active block used for modelling and transistor-level simulation are briefly discussed. The obvious chance for electronic tuning of the proposed filter is verified.