A novel voltage-controlled ring oscillator based on nanoscale DG-MOSFETs

Equipped with two closely coupled channels, double gate (DG) MOSFETs can locally and dynamically alter the front gate threshold by an applied back-gate bias in independent drive (IDDG) configuration. We illustrate in this paper how a conventional ring oscillator built using odd-number of CMOS inverters could be transformed to a robust, compact and high-sensitivity voltage-controlled oscillator (VCO) using this back gate tuning property. We explore the main design parameters of this VCO and analyze its tuning and jitter characteristics using SPICE simulations. The single or dual-biasing schemes explored here show that the nanoscale IDDG-MOSFETs are especially rewarding candidates for novel VCO/ICO circuitry targeted for low-power and compact systems.