Implementation of Current Starved Vco in 45nm Cmos Technology

Abstract

A Voltage Controlled Oscillator (VCO) is a ring oscillator that produces a periodic signal whose frequency is managed by a voltage input. A rising number of applications have necessitated the creation of low-power, high-speed oscillators in recent years. One promising design is the current starved ring oscillator, which controls the amount of current flowing in the inverter stages to regulate the frequency, hence these can be used rather than conventional ring oscillator. Basic principle of a current-starved VCO is using a pair of transistors in a cross-coupled configuration to form a feedback loop that produces a sinusoidal waveform. The voltage delivered to the transistors can be varied in order to change the oscillator's frequency. In this paper a current starved VCO is implemented in 45nm to produce stable frequency. The power, frequency aspects of it are observed and compared.