Advanced CMOS design

The course Advanced CMOS is central in the spcialization program of the IC gourp. It is required for the two main tracks: the data-converters and the RF electronics. The schema of IC gorup specialization and the position of the Advanced CMOS design course an be seen in the following scheme:

Learning objectives

By the end of the course, the students should be able to:

• analyze, synthesize and validate advanced analog CMOS integrated circuits
• read and use engineering articles on the CMOS IC design subjects and extract key ideas
• design CMOS circuits via a top‐down approach: identify what the basic architecture options are, identify what the major design trade‐ offs are, design and validate a solution
• discuss freely various design considerations on noise, mismatch, bandwidth, gain, time and frequency domain behavior

Content

This course arms students with broad theoretical knowledge on CMOS IC design (circuit analysis and synthesis) and specific design knowhow on important building components. The course reviews the most important concepts in modern CMOS design, identifies and repairs gaps in students' knowledge, and consequently builds a solid foundation for deeper future specialization in CMOS IC design.

This course discusses common fundamental limitations in CMOS IC design, like noise, mismatch, available voltage headroom, various non‐idealities and adequate methods and techniques on how to counteract and design for given specifications like gain, bandwidth, SNDR. Abstract formulations and rules are put in perspective with concrete transistor‐level examples, which are derived from real practical design challenges.

Thus, students are prepared for further specialization into more sophisticated concepts, methods and circuits needed for the CMOS design of data converters and RF transceivers.

This course is split in two simultaneously running parts: A and B. Part A is based on lectures that provide theoretical knowledge. Part B is based on group projects that provide practical experience.

PART A

In part A, this course will briefly refresh the foundations of analog CMOS design. Then, the contents will spread over the most important fields and subjects for modern microelectronics. Particular emphasis is put on the circuit design aspects.
The brief contents of the course per week are:

• Introduction and basics
• MOS transistor physics and fundamental circuits
• References
• Amplifiers
• Amplifiers
• Comparators
• High‐speed CMOS and CML logic
• Switched‐capacitor circuits
• Scientific and engineering papers

PART B

During part B of the course, the students have the opportunity to deepen their knowledge in a particular area through practical projects that will be closely supervised. These projects can be eventually used as starting point for more advanced internship and final Master projects. The students will be divided in groups of about 4‐5 students. Practical projects will be assigned to these groups. The students are expected to complete their projects and prepare a final report. Each of them will personally defend the project during the final oral examination. The approximate planning is as follows:

Week 2: Students present literature survey, project plan, and initial results;

Week 3: Students present project progress and intermediate results; all local simulations (DC, AC, parametric sweeps) need to be completed; first integrated simulation results need to be discussed.

Week 6: Discuss the first version of the final paper, structure, figures and writing plan; The students are required to submit the first version of their paper until week 7; All simulations and design choices need to be ready. The next design efforts will be on improving the final performance.

Week 8: Discuss the second version of the final paper. This version needs to be complete; the students are required to submit the second version of their paper until the end of the quartile; The design should be in its final shape.
 

Schedule

Part A:

• Introduction: Introduction to the course; Solid‐ state basics; Passive components: R, C, L and transformers; MOS transistors;
• MOS transistors: Noise; Mismatch; Equivalent circuits; Principles of CMOS design; Basic transistor circuits;
• References: Current sources, current mirrors, and references; Different architectures and main design trade‐offs; Basic layouts; The threshold referenced circuit; The band‐gap voltage reference;
• Amplifiers (part 1) – classification and basics; Main trade‐offs in amplifier design; Main amplifier types; Amplifier stability; Friis and Miller formulas; Boosting the gain; Linearization;
• Amplifiers (part 2) – design and stability compensation; Identify basic trade‐offs in OTA design; Understand stability compensation; Comment on various OTA architectures;
• Comparators: Synchronous vs. Asynchronous; Latch (positive feedback regeneration) concept; Reset; pre‐amplifier; Dual‐tail and StrongARM; current comparators;
• High‐speed CMOS and CML logic: Trade‐offs; Basic cells; Design considerations; Load‐Logic‐Current‐ source; Basic layouts; AC/DC margins; Ring‐oscillator test;
• Switched‐capacitor circuits: Concept of charge transfer; SC resistors; SC integrators; SC samplers; SC bandgap reference;
• Scientific and engineering papers;
   

Part B:

Design group project (Cadence);
Usually, the projects are about designing a CMOS building block in Cadence with a dummy CMOS 45nm design technology. Exemplary projects of previous years are:

• latch architecture investigation and design for high-speed and high-gain
• investigation of comparator architectures, with emphasis on dual-tail and strong-arm
• investigation of OTA architectures and design trade-offs
• filter design
• memory design
• proposed by students based on own ambitions

 

How to properly calculate the spectrum (FFT) can be found here: FFT tutorial

Entrance requirements

Assumed previous knowledge:

• 5CCA0 Semiconductor physics and materials
• 5ECB0 Electronic circuits 1

Information

dr. G.I. Radulov, PDEng MSc - FLX 7.089 - Tel. 5131