Integrated LC VCO Compatible with Memory Process for Gigahertz Clock Generation

This work presents the design and fabrication of the LC voltage-controlled oscillator (VCO) using 1-poly 3-metal CMOS process aimed for use in current memory manufacturing process. Poor characteristics of highly-resistive and immune to substrate-coupling metal-3 inductor in LC resonator were overcome by dual metal structure and patterned-ground shield (PGS) strategy. Fabricated VCO operated from 2.48 GHz to 2.73 GHz tuned by accumulation-mode MOS varactor. The corresponding tuning range was 250 MHz. The measured phase noise was - 113.5 dBc/Hz at 1 MHz offset at 2.48 GHz carrier frequency. The current consumption and corresponding power consumption were about 1.04 mA and 1.87 mW respectively.