Novel Circuit Topologies Will Address Challenges Due to Nanometer Transistor Scaling

Dr. Sam Palermo, assistant professor in the Department of Electrical and Computer Engineering at Texas A&M University, received the prestigious Faculty Early Career Development (CAREER) Award sponsored by the National Science Foundation (NSF).

Palermo received his CAREER award for his proposal, "Process, Voltage, and Temperature (PVT)-Tolerant CMOS Photonic Interconnect Transceiver Architectures.”

Palermo said the goal of his project is to develop robust energy-efficient transceivers for a unified inter- and intra-chip photonic interconnect architecture based on integrated ring resonator modulators and waveguide photodetectors. This is important because conventional off-chip electrical interconnects will not be able to increase their pin-bandwidths significantly due to channel-loss limitations. In contrast, silicon photonic interconnects provide a unique opportunity to deliver distance-independent connectivity, whose pin-bandwidth scales with the degree of wavelength-division multiplexing (WDM).

To accomplish this goal, Palermo said an ultrafast system-level optimization framework for photonic on-chip networks and inter-chip links that investigates tradeoffs in bandwidth density, energy efficiency and interconnect throughput will be developed. He adds that novel circuit topologies will be developed that address challenges imposed due to nanometer transistor scaling properties, such as transistor reliability constraints conflicting with voltage-swing requirements of optical source devices and shrinking transistor gain and growing mismatch having a large impact on receiver sensitivity. The combination of system level optimization with circuit-level accuracy and new ultra-efficient circuit topologies enables architectures capable of leveraging photonic interconnects’ properties of extreme low latency and high bandwidth to realize completely new computing models with orders of magnitude performance improvement.

He said the explosion in interconnect bandwidth capacity provided by these photonic interconnect architectures will allow the realization of numerous transformative applications, such as future smart mobile devices capable of Tflop/s performance, multi-channel high-resolution magnetic resonance imaging, and exascale supercomputers. Interconnect architectures developed with the proposed optimization framework will have a broad impact on not only the U.S. semiconductor industry, but also on the sustainability and security of the nation as a whole, as it will dramatically reduce the energy these integrated systems demand.

Palermo said he believes his project also will offer research opportunities to undergraduate students, underrepresented groups and high school students and teachers.

Palermo joined the Analog and Mixed Signal group in the electrical and computer engineering department in 2009. He received his B.S. and M.S. degrees in electrical engineering from Texas A&M, and his Ph.D. in electrical engineering from Stanford University. From 1999 to 2000, he was with Texas Instruments, where he worked on the design of mixed-signal integrated circuits for high-speed serial data communication. In 2006, he joined Intel Corp. where he worked on high-speed optical and electrical I/O architectures. His research interests include high-speed electrical and optical links, clock recovery systems, and techniques for device variability compensation. He is a member of IEEE and Eta Kappa Nu.

The NSF established the CAREER program to support junior faculty within the context of their overall career development, combining in a single program the support of research and education of the highest quality and in the broadest sense. Through this program, the NSF emphasizes the importance on the early development of academic careers dedicated to stimulating the discovery process in which the excitement of research is enhanced by inspired teaching and enthusiastic learning.