Lee/Sodini research teams announce new analog circuit design

February 16, 2007

EECS Professor and member of the Microsystems Technology Laboratories (MTL) Harry (Hae-Seung) Lee and his collaborators, including EECS Professor (and MTL member) Charles G. Sodini have developed a new class of analog circuits, comparator-based switched capacitor (CBSC) circuits, that have the potential, working with digital electronic circuits, to significantly boost the power and performance of current and future electronic devices.

The new CBSC analog circuit (in an 8-bit, 200 MHz analog-to-digital converter) was announced by the Lee-Sodini teams at the International Solid State Circuits Conference (ISSCC) in San Francisco Feb. 11-15, 2007. The first prototype MIT CBSC was demonstrated in an analog-to-digital converter presented at the 2006 ISSCC.

As reported in an MIT News Office February 15, 2007 article, Lee stated: "During the past several decades engineers have focused on allowing signals to be processed and stored in digital forms. But most real-world signals are analog signals, so analog circuits are an essential part of most electronic systems."

The problem is the inflexibility of the analog operational amplifiers which are employed in many of today's electronic devices. The revolution in software-developed digital circuits--including new fabrication techniques over the past decade--have resulted in reduced range of the analog signal and decreased gain. Additionally, analog circuits, which produce continuous yet variable output (as opposed to the discrete output values of digital signals), require in Lee's words: "clever designs by humans" ...in order to keep up with the developments of digital electronic circuits.

The Lee Sodini teams also include EECS graduate students John Fiorenza and Todd Sepke, who were involved in the work presented in 2006; EECS graduate student Lane Brooks, who worked on the current prototype; and Peter Holloway of National Semiconductor Corp.

The research leading to the 2006 ISSCC paper was funded by Microelectronics Advanced Research Corporation. The research leading to the paper presented to the recent ISSCC was funded by the MIT Center for Integrated Circuits and Systems and a National Defense Science and Engineering Graduate Fellowship.