Current-mode current-tunable four-phase quadrature oscillator

A current-mode current-tunable four-phase quadrature oscillator (QO) using current differencing transconductance amplifiers (CDTA) is presented in this paper. The proposed QO consists of three CDTAs and two grounded capacitors, which can provide four quadrature current outputs at high impedance nodes. The proposed QO has the advantages of electronically and independently control of oscillation condition and oscillation frequency. Moreover, the active and passive sensitivities of the QO are low. Cadence IC Design Tools 5.1.41 post-layout simulation results are included to confirm the theory.