A 3.3 GHz LC-based digitally controlled oscillator with 5kHz frequency resolution

Abstract

This paper reports a LC-based digitally controlled oscillator (DCO) with an enhanced frequency resolution and an extended linear frequency tuning range. It has a center frequency of 3.3 GHz. and a frequency tuning range of 600 MHz covered by 64 different frequency bands. Each frequency band has 2048 linear tuning levels with a frequency step of 5 kHz. This DCO was implemented in 90 nm CMOS and the measured frequency tuning characteristics arc provided in this paper. The DCO exhibits a phase noise of -11 NdBc/Hz. at 1 MHz frequency offset. The DCO core consumes 2 mA current from 1.2 V supply.