A 0.11mm2, 5.7-to-6.7GHz, parametrically pumped quadrature LC-VCO with digital outputs

We present a quadrature VCO based on mutual parametric pumping between two LC resonators. The design occupies 0.11mm2 in 65nm CMOS, consumes 16.8mW, and achieves a phase noise of -116.7dBc/Hz at 1MHz offset from a 6.57GHz carrier, while providing CMOS quadrature outputs. The measured phase error is less than 0.3° across the entire tuning range. Relative to state-of-the-art quadrature VCOs, it compares favorably in terms of area, phase accuracy and FoMA, making it attractive for area-constrained wireline and wireless SoCs.