A New Approach for Op-amp based VCO Design Using 0.18um CMOS Technology

A CMOS voltage controlled Op-Amp oscillator based on N-stage single-ended chain of different inverter types is described in this paper. This paper describes a performance and comparison of a ring oscillator based VCO and an Op-Amp based oscillator based VCO. The VCO is intended to operate in a op-amp based VCO to generate local oscillator frequency for an system. An oscillator topology an improved phase noise performance is proposed in this paper. It exploits the time-variant phase noise model with insights into the phase noise conversion mechanisms. The paper presents a new circuit technique intended to improve the voltagecontrolled oscillators (VCO) designs. It introduces a new, extremely simple, sinusoidal oscillator based on 0.18 um BSIM Technology Op-amps. The circuit employs only four components, two internally compensated op-amp, one resistor and a grounded capacitor, and can generate sinusoidal oscillations of frequencies up to the gain bandwidth product of the op-amps. With some modifications, using an additional op-amp or two analogue multipliers, the circuit can be readily converted into a VCO. We can also NMOS implementation for these. Although simulations indicated that future technology nodes could perform the necessary computation with full-swing static logic by using microwind software. Keywords— phase noise, voltage-controlled oscillator (VCO). ring oscillator, CMOS, Operational amplifiers