Fully integrated 10 GHz CMOS LC VCOs

10 GHz fully integrated LC VCOs suitable for data clock recovery architectures in optical receivers of SDH (STM-64) and SONET (OC-192) were designed and implemented in a 0.18 /spl mu/m 6-metal-layer standard digital CMOS technology. The performance of an injection ring type and cross-coupled type LC VCOs with three different varactor versions has been tested. All VCOs present reasonable phase noise performance and tuning characteristics under 1.8 V power supply.