A bond-wire inductor-MOS varactor VCO tunable from 1.8 to 2.4 GHz

This paper presents a technique that optimizes LC-tank CMOS voltage-controlled oscillators (VCOs) by minimizing the product of phase noise and power consumption. Moreover, it shows that the minimum depends on the tank's quality factor Q, the device noise coefficient γ, and the ratio between the maximum oscillation amplitude and supply voltage α. Prototypes, realized in a 0.35-μm process, show the following performances: -122.5 dBc/Hz at 600 kHz from a 1.9-GHz carrier, with 2-V supply voltage and 1-mA current consumption. The VCO can be tuned between 1.8-2.4 GHz, when the varactor control voltage is varied between 0-3.5 V. In the proposed realization, the tank is made of a metal-oxide-silicon varactor (operated between accumulation and deep depletion) and a bond-wire inductor, realized connecting two pads to a package frame lead to be compatible with the production environment