A 3GHz VCO suitable for MIPI M-PHY serial interface

This paper proposes a VCO which is based on a pseudo-differential ring oscillator scheme and it is suitable for multi-Gbps serial interfaces. The ring oscillator topology is based on two CMOS inverters loaded by a simple negative resistance realized with pMOS transistors. The circuit performance is compliant with the MIPI Alliance M-PHY standard which is the most updated high-speed serial interface technology. The circuit is designed and simulated in a 65nm CMOS process with 1.2 V supply voltage. The frequency tuning range was 1.9 to 3.5 GHz with an almost constant K_VCO equal to 5.7 GHz/V, approximately, while the current consumption was 6.4 mA at 3 GHz operating frequency and the phase noise was -94 dBc/Hz at 1 MHz frequency offset.