A Mixed-Signal Approach to Phase-Locked Loops

by Prof. Michael H. Perrott, Electrical Engineering and Computer Science Massachusetts Institute of Technology, USA

 :  22 Aug 2005 (Mon)
 :  10:00am - 12:00noon
Venue  :  Room 2504, 2/F (Lifts 25-26) HKUST

Phase locked loops (PLL) are widely used to create accurate frequency sources, and thereby form an integral part of all communication systems and most modern computation systems. The challenge of future PLL implementations is to achieve excellent noise performance at high frequencies within fabrication processes that are becoming progressively less friendly to pure analog circuit implementations.

In this talk we present several new PLL structures that offer improved noise performance by leveraging architectural innovation within heterogeneous (i.e., mixed-signal) frameworks. In particular, we present a wide bandwidth fractional-N synthesizer that achieves significant noise suppression through appropriate combination of analog and digital design and the application of signal processing techniques. We then present a clock and data recovery architecture that leverages the fractional-N synthesizer structure to robustly achieve low jitter in the presence of high leakage currents, as encountered in current fine-linewidth CMOS processes. Finally, we present an optical/electrical PLL topology that achieves low jitter by leveraging a novel optical/electrical phase detector topology.

Michael H. Perrott received the B.S. degree in Electrical Engineering from New Mexico State University, Las Cruces, NM in 1988, and the M.S. and Ph.D. degrees in Electrical Engineering and Computer Science from Massachusetts Institute of Technology in 1992 and 1997, respectively. From 1997 to 1998, he worked at Hewlett-Packard Laboratories in Palo Alto, CA, on high speed circuit techniques for Sigma-Delta synthesizers. In 1999, he was a visiting Assistant Professor at the Hong Kong University of Science and Technology, and taught a course on the theory and implementation of frequency synthesizers. From 1999 to 2001, he worked at Silicon Laboratories in Austin, TX, and developed circuit and signal processing techniques to achieve high performance clock and data recovery circuits. He is currently an Assistant Professor in Electrical Engineering and Computer Science at the Massachusetts Institute of Technology, and focuses on high speed circuit and signal processing techniques for data links and wireless applications.

*** All are Welcome ***