1 ~ 3 GHz VCO with rail-to-rail V-CONT range

Abstract

This paper presents a 1 similar to 3 GHz voltage controlled oscillator (VCO) with a rail-to-rail VCO tuning voltage (V-CONT) range. To obtain wide and linear V-CONT range, a new differential amplifier with a rail-to-rail common mode input range and an unstacked output stage is proposed. By using the proposed differential amplifier in the analog fine tuning block, V-CONT can span almost the rail-to-rail supply voltage with good linearity. For verification, a prototype VCO was fabricated in a 65 nm 1P7M CMOS process.