ECE483
ECE483 (Analog IC Design) is a 3-credit-hour senior level course that satisfies the Technical Electives requirement for ECE majors. It is offered only in the spring.
Content Covered
- MOSFET as a physical structure
- Parasitic effects in MOSFETs
- Current mirrors
- Single-transistor amplifiers
- Cascoded amplifiers
- Pseudo and fully differential amplifiers
- Common and differential mode half-circuit analysis
- Operational-transconductance amplifiers
- Folded-cascode differential amplifiers
- Bias circuitry design
- Figures of merit for differential amplifiers
- Feedback amplifiers
- Closed-loop and open-loop characteristics
- Low-dropout regulators
ECE483 primarily builds directly off the small-signal models of MOSFETS introduced in ECE342. The majority of the class focuses on the design of amplifiers, specifically differential amplifiers. Several different toplogies for amplifiers are discussed, alongside the tradeoffs presented by each topology. Figures of merit, such as input common-mode range (ICMR), common-mode rejection ratio (CMRR), and power supply rejection ratio (PSRR) are introduced alongside traditional figures of merit, such as bandwidth, gain, and power consumption.
Assignments focus on reinforcing concepts discussed in lectures. Homeworks are typically paper-pencil assignments involving analysis of given circuits consisting of transistors and typically either cover specific analysis methods, e.g. current mirrors or half-circuit analysis, or focus on calculation of figures of merit, such as common-differential mode gain in an amplifier or compliance range for current mirrors. Mini-projects are done in Cadence Virtuoso and focus on designing and simulating amplifiers in Spectre to meet given specifications.
The course begins with a discussion of physical integrated-circuits and MOSFETs, before moving onto process variations and their effects on ideal small-signal models. Device sizing is discussed alongside DC bias methods, and the gm-over-id method for device sizing is introduced. Single transistor and cascode amplifiers are discussed next, leading into a discussion of differential amplifiers and building up towards the operational-transconductance amplifier. Multiple lectures are spent on various topologies and design considerations.
Prerequisites
A solid understanding of ECE342 material, specifically small-signal analysis of MOSFETs, is required for ECE483. Students should be very familiar with the MOSFET: physical structure, DC analysis, and small-signal AC analysis. Some knowledge of control systems is also helpful in order to understand some of the theory regarding gain, bandwidth, and phase margins of amplifiers.
When to Take It
Take this course if you have an interest in analog integrated circuits and circuit design. As the course relies heavily on material from ECE342, it is best to take this course immediately afterwards.
Course Structure
ECE483 has a hefty workload. Homework is assigned weekly. Some problem sets mainly consist of circuit analysis problems relating to content covered in the course; others are design problems, requiring students to design and simulate the amplifiers discussed in the course. Homework assignments often take significant effort to complete, around 10 hours each week. Solutions to the homeworks are released the day before they are due, allowing students to check their work and clear up any confusion before submitting the homework.
The course also has two midterm exams and a final design project. Homework assignments and mini-projects are not assigned once the final project is released. In Spring 2024, the final project involved design of a low-dropout regulator, requiring certain specifications to be met via simulation.
Expect to spend 8-11 hours a week on this course.
Instructors
This course is taught by Professor Hanumolu, who is very experienced in analog circuit design.
Course Tips
Do not skip lectures. Lecture notes are posted, as are lecture videos, but unless you actively interact with the class by asking questions during lecture, it will be difficult to fully understand all the material covered in the course.
One of the earlier homeworks will involve heavy simulation of NMOS and PMOS transistors, obtaining graphs for various characteristics. This homework is exceptionally important for the gm-over-id method and should be done with great care to ensure the graphs obtained are accurate.
Work with other students to solve the homeworks and on the mini-projects. They are individual assignments, but take significant effort to complete solo. Working with other students also allows you to gain additional insight, as their approach may be different than yours.
Learn how to quickly analyze circuits, make approximations, and figure out what parasitics/effects are important to consider and when. Complete analytic analysis of the circuits presented is intractable and will waste a lot of time.
Life After
Students who have taken ECE483 have an introduction to analog integrated circuit design. Students interested in analog design should consider ECE486 - Control Systems, as analog IC design heavily relies on control theory, and ECE581 - Advanced Analog IC Design, the sequel to this course. In addition, students can consider other integrated circuits courses, including ECE425 - Intro to VLSI System Design and ECE482 - Digital IC Design, as well as semiconductor courses, including ECE441 - Physics and Modeling of Semiconductor Devices and ECE444 - IC Device Theory & Fabrication.
Resources
Course notes serve as the 'textbook' for the class. Recommended Textbook: Gray, Hurst, Lewis, Meyer, Analysis and Design of Analog Integrated Circuits, Wiley, 5th Edition