VCO Fundamentals

Presented by:  John McNeill, Director of the New England Center for Analog and Mixed Signal Integrated Circuit Design (NECAMSID), Worcester Polytechnic Institute

Outline:

Functional Block Concept
Input-Output Relationships
Basic Performance Metrics
- Center Frequency
- Tuning 'Constant'

Types of VCOs
- Resonant (LC, SAW based, crystal)
- Multivibrator
- Ring Oscillator

Methods of Tuning
- Varactor (voltage controlled capacitance)
- Drive strength (e.g. charging current in multivibrator)
- Phase adjust (interpolating) 

Second Order Performance Metrics
- V-f Linearity
- Supply/Load Sensitivity
- Phase Noise

Comparison of VCOs
Summary

Presenter Bio:
John McNeill received his bachelor’s degree from Dartmouth College in 1983, his master’s from the University of Rochester in 1991, and his Ph.D. from Boston University in 1994. From 1983 to 1990 he worked in industry on the design of high speed, high resolution analog-to-digital converters and low noise interface electronics used in high speed, wide dynamic range imaging systems. Since 1994 he has been with the Electrical and Computer Engineering department of Worcester Polytechnic Institute, where in 1999 he received WPIs campus-wide award for outstanding teaching. In 2006, McNeill and co-authors Michael Coln and Brian Larivee of Analog Devices received the Lewis Winner Award for outstanding paper at the 2005 ISSCC. His research interests are in the areas of analog and mixed signal integrated circuit design for phase-locked loops, analog-to-digital converters, and instrumentation.