Relative Design Merits and Trends in Single-Ended Ring Voltage Controlled Oscillators

Abstract

Voltage controlled oscillator (VCO) is one of the most crucial components in nanometer-scale circuits for communication systems. Wide tuning range, low power demand and high operating frequency are the key features that researchers tend to focus on while designing VCOs for submicron CMOS architectures. Reported topologies of oscillators reveal the existence of two widely employed VCO designs: the inductor-capacitor (LC) VCO and the ring VCO. This review article focuses on the single-ended ring oscillator (SERO), which is classified into different categories based on topology and performance. Along with basic architectures, state-of-the-art designs that have been proposed over the years are discussed in details highlighting their relative merits. Their performances are compared and presented in a tabular form in terms of key design figures which demonstrates that modifying existing SEROs typically requires trade-offs among oscillating frequency, power dissipation, tuning range and phase noise. The analysis also suggests the application specific use of the different architectures with respect to these properties. The comprehensive review will be a suitable literature for future work.

KEYWORDS:

• Adapted ring oscillator
• Conventional ring oscillator
• Hybrid ring oscillator
• LC-based ring oscillator
• Ring VCO
• Single-ended

Additional information

Notes on contributors

S. M. Ishraqul Huq

S M Ishraqul Huq received his BSc in electrical and electronic engineering (EEE) from Ahsanullah University of Science and Technology (AUST), Bangladesh in 2016. At present, he is a faculty member in the same department. He has been pursuing MSc in EEE from Bangladesh University of Engineering and Technology (BUET). His research interests include digital and analog/mixed-signal circuits. Corresponding author. Email: [email protected]

Apratim Roy

Apratim Roy received his BSc, MSc and PhD from the Department of EEE, BUET. He is currently serving as an associate professor in the same department. His research interests involve micro and nano-electronics, CAD of mixed-signal/RF architectures and RFIC design for wireless/broadband networks. Email: [email protected]