TUTORIALS
T2: Design and Simulation of Analog/RF Integrated Circuits with Open-Source CAD Tools and Process Design Kits
14:00 - 17:30 ROOM R3
CHAIR
Carlos Galup-Montoro (Universidade Federal de Santa Catarina, BR)
ABSTRACT
The open-source ecosystem offers IC designers endless innovation opportunities. Open-source CAD tools and PDKs enable engineers to design and simulate ICs without proprietary software, promoting collaboration, especially in academia. IC design needs MOSFET models that balance complexity and accuracy. Traditional textbook models are often oversimplified, while BSIM models in PDKs are highly complex. Bridging this gap is crucial for efficient IC design. This tutorial introduces ACM2, a minimalist single-piece model for open-source simulators like Ngspice, covering all DC characteristics and small-signal equations. Attendees will learn about the ACM2 DC and small-signal characteristics, how to extract the model's 5 DC parameters using the IHP 130 nm open PDK, and how to use the model to simulate integrated circuits in an open-source CAD environment. Applications of ACM2 to basic analog/RF building blocks and hands-on design examples in IHP 130 nm technology will be presented.
PROGRAM
14:00 - 14:30
All-Region Single-Piece MOSFET Theory
Carlos Galup-Montoro (Universidade Federal de Santa Catarina, BR)
The tutorial begins by summarizing a novel charge-based MOSFET model, denoted ACM2, including velocity saturation and drain-induced barrier lowering.
The main advantage of ACM2 is that the effect of saturation velocity is included in the charge control equation through the saturation carrier charge in order to avoid the definition of a saturation voltage and the use of interpolation functions to link the triode and saturation regions. Consequently, ACM2 consists of single-piece equations derived from physics.
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14:30 - 14:50
Implementing the ACM Model
Manuel J. Barragan (CNRS, TIMA LaboratoryM, FR)
This talk will describe in detail the practical implementation of the ACM2 model for its use in numerical simulators. We will especially focus on efficient methodologies for solving the transcendental equations linking inversion charge and node voltages. Two strategies will be considered: a classical numerical approximation and a novel analytical approximation of the Lambert function that may lead to a closed form I-V MOS equation.
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14:50 - 15:30
ACM Parameter Extraction
Deni Germano Alves Neto (TIMA LaboratoryM, FR, and Universidade Federal de Santa Catarina, BR)
This part of the tutorial will cover the extraction of the five DC parameters of the ACM2 model. While the quality of a compact model is essential, its predictive accuracy ultimately depends on how well its parameters are extracted. The DC core of the ACM2 model has just five physics-based parameters: three for long-channel behavior (VT0, IS, and n) and two for short-channel effects (sigma and zeta). A key advantage of this minimal set is that each parameter can be extracted through a straightforward method. The extraction process will be demonstrated using open-source EDA tools alongside the IHP 130 nm Open PDK.
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15:30 - 16:00
Coffee break
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16:00 - 16:45
RF Circuit Design
Sylvain Bourdel (TIMA Laboratory, FR)
On the basis of ACM model presented in the previous talk and with the help of the open source CAD tools introduced with the extraction method, we present an analytical design method for an LNA. This method uses the inversion level to explore the design space, accounting for Noise, Gain, Power and Linearity characteristics. This design flow will be illustrated with open source tools and the speaker will provide online material to help attendees.
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16:45 - 17:30
Analog Circuit Design
Marcio Cherem Schneider (Universidade Federal de Santa Catarina, BR)
This part of the tutorial describes the application of the ACM2 model to analog circuits. ACM2 is an accurate MOSFET model that fulfills the requirements for an appropriate analog design. It will be shown how the unified current control model (UICM), which describes the relationship between the inversion coefficient and the terminal voltages, can be used for the synthesis of analog blocks. Some basic circuits such as current mirrors, single-stage amplifiers, and current and voltage references will be used to demonstrate the usefulness of the ACM2 model to their analysis and synthesis.
BIOSKETCHES
Carlos Galup-Montoro (Chair)
Carlos Galup-Montoro (Life Senior Member, IEEE) studied Engineering Sciences at the University of the Republic, Montevideo, Uruguay, and Electronic Engineering at the National Polytechnic School of Grenoble (INPG), France. He received an Engineering degree in electronics in 1979 and a doctorate degree in 1982, both from INPG. From 1982 to 1989 he worked at the University of São Paulo, Brazil. Since 1990 he has been with the Department of Electrical and Electronics Engineering, Federal University of Santa Catarina, Florianópolis, Brazil, where he is currently a professor. In the second semester of the academic year 1997-1998 he was a research associate with the Analog Mixed Signal Group, Texas A&M University. He was a visiting scholar at UC Berkeley from 2008 to 2009 and at IMEP/INPG in the first trimester of 2017.
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Deni Germano Alves Neto
Neto Deni Germano Alves Neto (Student Member, IEEE) received the B.S. degree in electronics engineering and the M.Sc. degree in integrated circuits and systems from the Federal University of Santa Catarina (UFSC), Florianópolis, Brazil, in 2018 and 2022, respectively. He participated in a year-long exchange program at Worcester Polytechnic Institute, Massachusetts, USA, in 2014/2015. He conducted ultra-low-voltage/ultra-low-power IC design as a research assistant with the Integrated Circuits Laboratory, UFSC. He is pursuing a joint Ph.D. between UFSC and Université Grenoble Alpes, France, in the TIMA laboratory. His Ph.D. research includes analog/RF and open-source IC design and the development of an advanced compact MOSFET model for IC design and simulation. He has participated in several open-source IC design initiatives: the 2021-2023 SSCS PICO Contest and the 2023-2024 UNIC-CASS. He is also a recipient of the NEWCAS 2023 Best Paper Award.
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Manuel J. Barragan
Manuel J. Barragan received an M.Sc. degree in Physics in 2003 and a Ph.D. in Microelectronics in 2009, both from the University of Seville, Spain. He is currently a Research Director with the French National Research Council (CNRS) at TIMA Laboratory, France, where he leads the Reliable RF and Mixed-Signal Systems group. His research is focused on the topics of design and test of analog, mixed-signal, and RF systems.
His Ph.D. research won a Silver Leaf Award at the IEEE PRIME conference in 2009 and, in 2011, his work was selected for inclusion in the 20th Anniversary Compendium of Most Influential Papers from the IEEE Asian Test Symposium. He received the Best Special Session Award in the 2015 IEEE VLSI Test Symposium, the Best Paper Award in the 2018 IEEE European Test Symposium, and the Best Paper Award in the 2023 IEEE NEWCAS conference.
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Sylvain Bourdel
Sylvain Bourdel received the Ph.D. in microelectronics from the National Institute of Applied Science (INSA) of Toulouse in 2000. He was with the LAAS laboratory of Toulouse where he was involved on radiofrequency systems modelling and he was especially focused on spread spectrum techniques applied to 2.45GHz transceivers. In 2002 he joined the IM2NP in Marseille where he headed the Integrated Circuit Design team. Meanwhile, he was expert for the SCS world-class clusters and the ARCSIS cluster and member of the National Council of Universities (CNU). He joined in 2013 the IMEP-LaHC laboratory and Grenoble-INP as a full Professor. From 2018 to 2021, he was the director of the RFIC-Lab laboratory of Grenoble, France. He is now with the TIMA laboratory. He was the co-general chair of NEWCAS 2021, Technical Program Chair of NEWCAS 2015, Financial chair of ICECS 2024 and member of the NEWCAS steering committee. He is actually the secretary of the French CAS chapter and counselor of the Grenoble IEEE student branch. He works on RF and mmW IC design and integration. He particularly focuses on low cost and low power applications. His area of interest also includes design-oriented MOS modelling, UWB and BIST for RF&mmW circuits.
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Márcio Cherem Schneider
Márcio Cherem Schneider (Life Senior Member, IEEE) received the B.E. and M.Sc. degrees in electrical engineering from the Federal University of Santa Catarina (UFSC), Brazil, in 1975 and 1980, respectively, and the Doctorate degree in electrical engineering from the University of São Paulo, São Paulo, Brazil, in 1984. In 1976, he joined the Electrical Engineering Department, UFSC, where he is currently a professor. In 1995, he spent a one-year sabbatical with the Electronics Laboratory, Swiss Federal Institute of Technology, Lausanne. In 1997 and 2001, he was a Visiting Associate Professor with Texas A&M University.