Package Aware LC-VCO With Self-Biased Switched Capacitor Structure for Better Supply Noise Rejection

This article proposes a packaged standalone LC-voltage-controlled oscillator (VCO) based on self-biased (SB) switched capacitor array (SCA) to facilitate large frequency tuning-range (TR). The proposed SB SCA achieves better supply noise rejection and is robust to quad flat no-lead package (QFN) package parasitics when compared with other existing SCA topologies without compromising the quality factor (Q-factor) of the SCA in OFF-state. A prototype SB SCA-based LC -VCO designed and fabricated in United Microelectronics Corporation (UMC) 65-nm complementary metal oxide semiconductor (CMOS) process oscillates from 1.54 to 2.54 GHz having a TR of 40% achieving a phase noise (PN) of ≈-96 dBc/Hz at 100 kHz offset and an figure of merit (FoM) of ≈174 dBc/Hz at 100 kHz offset while consuming 10 mW of power from 2.5 V supply, thereby making it ideal for applications requiring QFN-packaged standalone VCOs.