Laurence W. Nagel

Computationally efficient electronic-circuit noise calculations

The interreciprocal adjoint network concept is applied to the computer simulation of electronic-circuit noise performance. The method described is extremely efficient, allowing consideration of an arbitrarily large number of uncorrelated noise sources with less effort than for the original small signal a.c. analysis. Because all noise sources may be considered, no a priori assumption need be made as to which noise sources are dominant in a complicated circuit. The method is illustrated with an operational- amplifier example.

Computer analysis of nonlinear circuits, excluding radiation (CANCER)

CANCER is a reasonably general circuit analysis program especially suited to integrated-circuit simulation. The program provides for the analysis of large circuits in the following four modes of operation: nonlinear d.c., large-signal transient, small-signal a.c., and thermal and shot noise. These subanalysis capabilities are intercoupled appropriately for convenience and efficiency. Internally, CANCER is a very general nodal analysis program that derives its efficiency from the exploitation of sparse matrix, adjoint, and implicit integration techniques.

Early effect modeling in SPICE

The approximations made in the Early effect formulation of the SPICE Gummel-Poon bipolar junction transistor (BJT) model were reasonable when the model was first developed but introduce unnecessary inaccuracies when modeling the output conductance of modern BJTs. In this paper, we give the reason the original approximations were made, present a new way to plot data to best show the Early effect, and detail a new, consistent, coupled method to determine forward and reverse Early voltages.

Best Practices for Compact Modeling in Verilog-A

Verilog-A is the de facto standard language that the semiconductor industry uses to define compact models. Unfortunately, it is easy to write models poorly in Verilog-A, and this can lead to unphysical model behavior, poor convergence, and difficulty in understanding and maintaining model codes. This paper details best practices for writing compact models in Verilog-A, to try to help raise the quality of compact modeling throughout the industry.

CANCER: Computer analysis of nonlinear circuits excluding radiation

Cancer is a program designed for the complete simulation of integrated electronic circuits, possessing the following features:

The 40th Anniversary of SPICE: An IEEE Milestone [Guest Editorial]

SPICE (Simulation Program with Integrated Circuit Emphasis) is ubiquitous in the electrical engineering profession. For 40 years now, engineering students have learned how to use SPICE as undergraduates, have employed SPICE in their graduate research, and have embarked upon careers in electrical engineering where they have relied upon SPICE in the design of electronic circuits.

Professor, Visionary, Friend

I first met Don Pederson in the fall of 1966 when I attended my first session of EE105 (Electronic Circuits). My first impression of Don was that he was a character. Thank goodness Don never made any attempt to hide the fact that he was a character! He not only had a marvelous understanding of electronic circuits, but he also knew the people who designed the circuits and the companies that were nurturing those people and fueling the innovations that were transforming Silicon Valley into a technological and economic powerhouse. When you took a class from Don, you were not just learning circuit design, you were becoming a part of a new and exciting industry.

CANCER: Computer Analysis of Nonlinear Circuits Excluding Radiation

Cancer is a program designed for the complete simulation of integrated electronic circuits, possessing the following features:

Circuit simulation and design methodology

The continued increase in the size and complexity of integrated circuits (ICs), along with an increasing number of constraints on various aspects of IC behavior and performance, have led to an ever-growing “check list” of items that must be taken into account during the IC design process and should be verified by simulation before committing to tape-out. This session includes 5 papers that report developments in several important aspects of methodologies for circuit design and simulation.

Advanced MOS modeling techniques

With each new CMOS technology node, device dimensions decrease and the underlying physics that determines the device electrical characteristics becomes more complicated. Physical phenomena that could be neglected in previous technology nodes become fundamental to device operation, so advancing technology imposes evermore stringent requirement on device modeling. This session presents five papers that describe advances in the state of the art of MOSFET modeling.