A UMTS-complaint fully digitally controlled oscillator with 100Mhz fine-tuning range in 0.13/spl mu/m CMOS

Abstract

A 0.13mum CMOS fully digitally controlled oscillator is presented. Running at 2GHz, it draws 3.2mA from a 2.5V supply and has a phase noise of -118dBc/Hz at 1MHz offset, as required for UMTS oscillators. A tuning range from 3.45 to 4.45GHz is achieved by using binary-weighted and thermometer-coded switchable capacitors, which allow a maximum frequency step of 200kHz