An Ideal Voltage-Mode All-Pass Filter and Its Application

A new first order voltage mode all-pass filter circuit using two differential difference current conveyors (DDCCs) (with suppressed output stages) as active elements and two passive components is proposed. The given circuit enjoys the features of high input impedance and low output impedance, which is desirable feature for voltage-mode circuits. In spite of employing two active elements the circuit requires only twenty transistors in all, thus providing a simpler solution than some recent one active element based circuits. It also has low active and passive sensitivities. The circuit has useful analogue signal processing application as a multiphase oscillator. PSPICE simulation using 0.5μm CMOS parameters are given to validate the proposed circuit.