Automated synthesis of integrated RF CMOS LC VCOs

This paper presents an example of analog RF circuit synthesis, namely an LC-VCO for Bluetooth. Transistor sizing is carried out using a simulation-based genetic Optimization tool called AMIGO;. The synthesized example leads to a 2.4-GHz fully integrated LC voltage-controlled oscillator (VCO) using 0.35-μm CMOS technology. The simulated phase-noise values are found to be –112, -107, and -106 dBc/Hz at 600 kHz offset from 2.1, 2.4, and 2.7 GHz carriers, respectively. The VCO consumes 4.77 mA from a 3.3-V supply voltage. An accumulation-mode MOS varactor is used to achieve 25% of tuning range, The MOS varactor and the on-chip spiral models are taken from a standard cell library provided by the foundry.