Integrating Mixed Signal IC Design Research into a Project-based Undergraduate Microelectronics Curriculum

John A. McNeill, Richard Vaz

Electrical and Computer Engineering Dept., Worcester Polytechnic Institute

100 Institute Road, Worcester, MA 01609

ABSTRACT

This paper describes the integration of project based education and the design of mixed signal integrated circuits and systems at Worcester Polytechnic Institute (WPI). The flexibility of WPI's Projects Program allows a variety of undergraduate educational opportunities, including industry sponsored projects (both on- campus and overseas) as well as interdisciplinary work involving collaboration with researchers in other fields.

1. INTRODUCTION

Despite tremendous growth in the areas of computer engineering, software, and digital electronics, there is a persistent need for analog and mixed signal design engineers [1]. The needs of industry require designers to understand a broad range of disciplines, from the solid- state physics of submicron devices, through circuit-level techniques, to high-level system design and analysis. In addition to theoretical knowledge, the designer must also be constantly aware of manufacturability and testability issues. The increased pressure on educators and students to squeeze more information into the undergraduate curriculum demands the exploration of alternatives to traditional lecture/laboratory instruction. This paper describes project based education in the design of mixed signal integrated circuits and systems at Worcester Polytechnic Institute (WPI). The flexibility of WPI's Projects Program allows a variety of undergraduate educational opportunities. Examples that will be described in this paper include industry sponsored projects, both on-campus and overseas, as well as interdisciplinary undergraduate design projects involving collaboration with researchers in other academic departments.

2. EDUCATIONAL PHILOSOPHY

A. WPI's Projects Program

Founded in 1869, Worcester Polytechnic Institute is the third oldest private school of engineering and science in the United States. WPI has about 200 faculty, 2600 undergraduates, and 600 graduate students, and offers programs in engineering, the sciences, and management. In 1970, WPI adopted "The WPI Plan", an innovative undergraduate curriculum which focuses on outcome- oriented, project-based education. In addition to other degree requirements, all WPI undergraduates must complete two significant projects in order to graduate: the Interactive Qualifying Project (IQP) and the Major Qualifying Project (MQP). Both of these projects are done in small groups (typically three students) and in close collaboration with one or more faculty advisors. The IQP, typically done in the junior year, is an interdisciplinary project in which student teams address a problem relating technology and society. The MQP, typically done in the senior year, is a disciplinary project which constitutes a "capstone design experience" or "senior thesis" in the student's major area. Both of these project experiences emphasize the development of skills related to teamwork, open-ended problem solving, and oral and written communication. About 1/3 of all WPI undergraduates complete one of these projects (usually the IQP) at an off-campus site. WPI has IQP project programs in such places as Washington, San Francisco, Puerto Rico, Costa Rica, London, The Netherlands, Germany, Venice, and Bangkok. Students spend an academic term (2 months) at one of these sites completing their project under the on-site supervision of a WPI faculty member.

B. ECE Department Curriculum

Students must acquire a broad range of skills to succeed in this project-oriented program. These are the same skills that our graduates will need in an increasingly competitive global marketplace: The project-oriented philosophy is present throughout the curriculum, beginning with introductory courses that give an overview of the entire ECE field, and continuing to advanced courses that deliver targeted knowledge required to perform advanced project work. The entry point of the ECE curriculum is EE2011, "A Project-Oriented Introduction to Electrical and Computer Engineering." [2] This course is usually taken by students at the end of the first year, and as the title indicates, the emphasis is on a hands-on, project-oriented introduction to the field of electrical and computer engineering. The students are encouraged to think at a system level: what kind of problems are addressed by electrical and computer engineers? Once students encounter this overview of the engineering profession, they are better motivated to learn the basic principles and inner workings of the systems they have seen. Subsequent courses follow a "spiral curriculum" in which knowledge is built up in successive levels of detail, while continuing to revisit the system-level issues that underlie the engineering design process. For students who wish to perform their MQP in the area of mixed signal integrated circuit design, the undergraduate microelectronics curriculum has recently been restructured so that the advanced analog integrated circuit design course is available at the end of the junior year. In this way, students entering the senior year will be able to complete a mixed signal integrated circuit design as their MQP project.

C. Mixed Signal Design Research Lab

A major part of the ECE department's commitment to project-based education is the Mixed Signal Design Research Laboratory, under the direction of Prof. McNeill. The laboratory facility comprises a complete integrated circuit design and test environment, and is an integral part of the project experience in analog and mixed signal integrated circuit design. Funding from industry partners Analog Devices and EG&G Reticon and the National Science Foundation [3] was used to equip the lab with workstations, CAD software, and test instrumentation. Integrated circuit fabrication is available through MOSIS and the industry partners. The result is a facility that allows project students to experience the complete circuit design and simulation process: schematic capture, simulation, layout, parasitic extraction, layout-vs.-schematic verification, fabrication, test, and evaluation. Students participating in on-campus projects have full access to this lab. The goal is an education that produces a design engineer who is knowledgeable in all stages of the design process including manufacturing, testing, and meeting the end customer's application requirements.

3. PROJECT EXAMPLES

A. Electronic Power Metering

Analog Devices, Limerick, Ireland

Projects at this MQP site involve a team of three students designing application circuitry to interface with the integrated circuit products that are developed at sponsor Analog Devices' Limerick facility. Given the nature of mixed signal integrated circuits, the design process also includes work in the areas of analog, digital, system, and software engineering - just the sort of interdisciplinary, cross-cultural design process that is difficult to teach within a traditional engineering program, but is essential for success in the global workplace.

The project completed in 1996 involved development of application circuitry for the AD7750 Product-to-Frequency converter. The project team designed circuitry to implement single-phase and three-phase power meters using the AD7750. The circuitry was designed to meet the customer's system-level requirement to replace mechanical meters with an electrical meter that can be read remotely. Design of the three-phase meter involved a novel approach to the problem of combining the digital outputs of three (non-synchronized) converter chips. In addition, software was developed to provide a graphical user interface to the meter, as well as to demonstrate and test its operation.

B. pH Meter-on-a-Chip IC Design

Biomedical Engineering Collaboration

This project, now underway in the 1996-97 academic year, is an example of the interdisciplinary research that can be conducted within the framework of an undergraduate mixed-signal IC design project. This project is in collaboration with researchers in WPI's Biomedical Engineering department and the University of Massachusetts Medical Center in Worcester. The three-student project team is designing an integrated circuit for a hand-held pH meter, that must meet requirements which are defined at a very high level by the research "customer." The IC must allow speedy measurement of tissue acidity, which has been determined to be an indicator of infection. From this broadly defined customer requirement, the student team must determine system level specifications and complete a circuit level design to meet the specifications. The IC will encompass all necessary functions for the instrument: interfacing to the pH probe, performing all necessary signal processing and data conversion, and driving an LCD readout to display measured pH.

C. BiCMOS PWM IC Applications

Unitrode Integrated Circuits Corp.

Projects sponsored by Unitrode are conducted on campus during three terms over the course of the academic year. These MQPs involve the design of applications circuits using power management ICs manufactured by Unitrode. The project now underway in the 1996-97 academic year involves design of circuitry using BiCMOS Pulse Width Modulation (PWM) ICs for high efficiency, closed loop controlled power supplies. One application senses the temperature in an enclosure (such as a computer) that is cooled by a fan, and controls the fan supply voltage (and fan speed) to save power when maximum cooling is not required.

4. CONCLUSION

The flexibility of a project-based approach to undergraduate education allows a variety of educational opportunities. The inherently interdisciplinary nature of the problems encountered in these projects provides an invaluable exposure to the issues involved in open-ended, "real-world" design.

REFERENCES

  1. E. Fossum et. al., "To be EE or not to be," ISSCC Digest of Technical Papers, pp. 264-275, Feb., 1997.
  2. J. McNeill and R. Vaz, "High Expectations: A Passport to Success," Ninth International Conference on the First Year Experience, July, 1996.
  3. J. McNeill, Research Instrumentation grant from the National Science Foundation Computer and Information Systems Engineering (NSF-CISE).
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