High output impedance current-mode all-pass sections with two grounded passive components

Two new first-order, current-mode all-pass sections, each with high output impedance and requiring only two grounded passive components along with a differential voltage current conveyor, are presented. The new circuits require no matching conditions for the realisation of current transfer functions and are simpler than most of the recently available circuits. The effect of parasitics and non-idealities is also considered. PSPICE simulations using 0.5 mu CMOS parameters confirm the validity and practical utility of the proposed circuits. A typical application in realising a new current-mode quadrature oscillator is given. A four-phase quadrature oscillator with high impedance outputs is also given.