Versatile insensitive current-mode universal biquad implementation using current conveyors

We present a versatile multi-input-multi-output biquad configuration. Either a three-input single-output or a single-input three-output universal filter can be realized. The proposed construction is comprised of only three current conveyors and four grounded passive elements, is multifunctional and convenient for monolithic integration, has low sensitivity, and is simple in structure. Its high impedance outputs enable easy cascading in current-mode operation. After slightly modifying an original configuration, another novel single-input three-output universal filter with extra advantageous features has been obtained. The effects of current conveyor nonidealities are discussed and simulation results are provided.