Multifunction double-integrator current-mode filter based on current mirrors

A multifunction current-mode biquad filter configuration with three inputs and one output using current mirrors is proposed in the paper. The filter uses two basic current mirrors and two unloss integrators, and can realize low pass, high pass, band pass, band reject and all pass filtering responses by changing input signal forms. Its related CMOs circuit is presented. The transfer function properties of the filter are analyzed. PSPICE simulation results show that the proposed circuit is valid, and the natural frequency of the filter can reach more than 10MHz. The circuit has several advantages, such as very low filter sensitivities, versatility, and suitability for fully integration.