Cmos single input multiple output universal biquad filter current-mode using only otas

This paper presents a new single-input multiple-output universal biquad filter in current-mode with only four operational transconductance amplifiers (OTAs) and two grounded capacitors. The proposed filter can be obtained all filtering functions, low-pass, high-pass, band-pass, bandstop and all-pass filter that the transfer functions of the filter can be selected by choosing appropriate current output without any component matching conditions. The natural frequency and quality factor of all filtering functions can be controlled electronically and orthogonally using the bias currents of transconductance amplifiers. The active and passive sensitivities of the filters are low. The proposed filter has been simulated using 0.18 μm CMOS process from TSMC. PSPICE simulation results are included to confirm workability of the proposed circuits.