Learning outcomes of the course unit
The course provides advanced knowledge required for approaching the design of Analog Integrated Circuits in CMOS technologies.
Course contents summary
Analog integrated circuits design: main differences and peculiarities with respect to discrete-components design.
Passive components in Silicon technologies (resistors, capacitors and inductors): parasitics and lumped models. MOS transistors: main parasitic effects, minimization of the capacitance at the drain terminal; multi-gate devices.
Process tolerance and component mismatch. Interconnection lines: lumped models. Pad, packaging and bonding: models.
Impact of the process tolerance and mismatch on the analog design: corner analysis and Monte-Carlo simulation.
Behavioral modeling of analog cells with Spectre-HDL.
Design of operational amplifier in CMOS technology
Two-stages opamp: basic and advanced Miller compensation techniques. Analysis of non-dominant poles and zeros in the transfer function of basic amplifier stages: cascode and differential amplifier. Folded-cascode opamp. CMRR and PSRR of two-stages opamp.
High-DC gain opamps: gain boosting technique. Low supply voltage opamps, rail-to-rail input opamps. Output stages. Micro-power opamps.
Differential output opamps: common-mode feedback and stability issues. Simulation techniques.
Noise sources in single stage amplifier and Miller-compensated two-stages opamps. Noise minimization techniques.
Design of special analog circuits in CMOS technology
Switched-capacitor circuits: sample-and-hold, amplifier and filters.
Voltage and current references: CMOS bandgap reference.
Theory of Analog Circuit Simulators
Analog Simulators: Spice, Spectre.
DC-OP analysis and algorithms: Newton-Rapson method. DC-OP issues and problems: continuation methods, initial condition, multiple operating points. Accuracy parameters: reltol, vntol and abstol
Transient analysis: integration methods: Euler, Trapezoidal, Gear2; how integration methods affects the simulation results. Accuracy parameters: lteratio, transient convergence criteria (pointlocal, sigglobal, etc.), maximum time-step.
Design of an analog circuit in CMOS technology (opamp, bandgap reference, etc.) using Cadence as CAD framework and Spectre as Simulator.
B. Razavi, ``Design of Analog CMOS Integrated Circuits'', Mc Graw Hill
P. E. Allen, D. R. Holdberg , "CMOS Analog Circuit Design", 2nd edition, Oxford University Press
K. S. Kundert, “The Designer's Guide to Spice and Spectre”, Kluwer Academic Publ.
The course is divided in two parts: lectures (theory of analog IC design in CMOS technologies) and laboratory of analog IC design.
The laboratory of analog design is based on projects of analog cells (previously illustrated in the lectures). The aim of the analog laboratory is the consolidation of knowledge provided in the lectures and providing a basic knowledge of analog design software (EDA CAD)
Assessment methods and criteria
The exam is oral.
Students have to provide the reports of every design projects of the Lab. activity during the Academic Year and within the deadlines communicated by the teacher.
The exam includes a discussion of the the results of the activity in the Analog Lab.