August 26-30, 2024

Registration deadline: July 20, 2024
Payment deadline: August 16, 2024

Download one-page schedule here

Course material will be distributed only if fees have been paid by the deadline for payment.

MONDAY, August 26

TUESDAY, August 27

WEDNESDAY, August 28

THURSDAY, August 29

FRIDAY, August 30

Advanced Analog Circuit Design
August 26-30, 2024
EPFL Premises, Lausanne, Switzerland

Analog Building  Blocks
Kofi Makinwa, TU Delft, The Netherlands

Analog integrated circuits consist of building blocks with one single or two transistors. The gain, input- and output impedance is analyzed of the three single-transistor stages i.e. the amplifier, the source follower and the cascode. The differential pairs, current source and inverter amplifiers are the most used two-transistor configurations. They are analyzed in detailed. Negative resistors are added for higher Gain and Gain-Bandwidth. Design procedures are discussed for all of them.

Stability of Operational Amplifiers
Kofi Makinwa, TU Delft, The Netherlands

Two-stage operational amplifiers in unity-gain configuration, suffer from peaking unless a compensation capacitance is added, or the current is increased in the second stage. These stability conditions are examined in detail, followed by five techniques to eliminate the positive zero. One of them is feedforward, which allows a gain of over a factor of two in power efficiency. The design plans are extended to three-stage amplifiers, which offer new stabilization opportunities.

Power Optimization
Kofi Makinwa, TU Delft, The Netherlands

“Built-In” voltages available in silicon. Circuits extracting thermodynamic voltage kT/q. Circuit extracting the bandgap voltage. Principle and properties of the bandgap voltage reference and its implementation in CMOS.

Analog Functional Blocks
Kofi Makinwa, TU Delft, The Netherlands

For minimum power consumption, two transistor parameters have to be chosen with great attention for speed and noise. They are the inversion coefficient or current density and the increased channel length. This is elaborated on by use of the full MOST model, including weak and strong inversion and velocity saturation. Designs plans and examples are given for single-, two- and three-stage amplifiers.

Distortion in Elementary Transistor Circuits
Kofi Makinwa, TU Delft, The Netherlands

In telecommunication applications, distortion has become important as it mixes the channel contents. Firstly the several parameters are derived to described distortion such as IM3, -1dB compression point , IMFDR3, etc. Then several sources of non-linear distortion are identified and analyzed for a MOST in all three regions of operation. Many numerical examples are included. Techniques for the reduction of distortion are discussed, such as differential operation and feedback. Finally distortion is analyzed for two-stage operational amplifiers.

Distortion Cancellation
Kofi Makinwa, TU Delft, The Netherlands

The application of feedback is not sufficient for ultra-low-distortion. Distortion cancellation techniques are introduced such as cross-coupling, paralleling, etc. The Quality of cancellation is investigated and compared for both static and dynamic ampliers. Circuits for simultaneous noise and distortion cancellations are included as well.

Offset and 1/f Noise Reduction Techniques
Kofi Makinwa, TU Delft, The Netherlands

The design of precision analog interfaces in CMOS is severely impaired by offset, offset drift and 1/f noise. The material covered in this module analyzes these impairments in detail and reviews the common solutions for their remedy: chopping, autozeroing, correlated double sampling and offset stabilization. We will discuss the residual nonidealities as well as pros and cons of each technique and review typical application examples. In addition, we will survey recent advances in the state-of-the-art.

CMOS Switched-Capacitor Circuit Design
Christian Enz, EPFL, Switzerland

Discrete-time signals, Laplace and z-transform; Basic building blocks (opamps, switches, capacitors); Sample-and-hold circuits; SC integrators, bilinear filters and and biquads; SC amplifiers; Correlated double sampling and chopper stabilization; Nonideal effects and their correction.

Practical Techniques of Frequency Compensation
Vadim Ivanov, Texas Instruments, USA

Every analog IC comprises multiple feedback loops. Interaction between these loops makes frequency compensation of such system non-trivial task, unsupported by the general control theory. Every MOS or bipolar transistor is nonlinear, which may cause conditional stability and complicate compensation.
We will consider system structure design for stability, needed for it elementary circuit cells additional to the textbook techniques, as well as ways to achieve unconditional system stability when component parameters vary, and when load and signal source impedance is not well defined. Examples include LDOs stable with any load capacitance, transconductors with wide (few volts) input voltage range, and multistage operational amplifiers.

Bandgap Voltage References
Vadim Ivanov, Texas Instruments, USA

Discussed are error sources of the bandgap voltage references and techniques for improving their accuracy: circuit techniques for low-noise bandgap generation core, feedback amplifier with chopping offset elimination, output buffer with mOhm output impedance and fast settling on load changes; single- dual and triple temperature trimming; packaging requirements; testing and application particulars. Also presented circuit solutions for reverse bandgap reference, operational from 0.9V supply, and reference structure and implementations with nanoampere consumption.

Techniques for OpAmp Speed and Accuracy Improvement
Vadim Ivanov, Texas Instruments, USA

Presented is a top down design process of the OpAmps based on the structural design methodology. We will start from selection of the gain structure, followed by the implementations of gain structures as well as gradual addition of various specific functions like PSRR/CMRR improvement, slew enhancement, overload recovery. We will consider offset improvement by trimming as well as by auto-zeroing and chopping, high-and low-voltage design specifics. Most of the circuits solutions were not published before and have been used in recent industrial ICs. Yet it is not another cookbook with analog circuit recipes. The goal of this presentation is to arm the engineers with a tool helping to invent the solution for any analog design problem and, at the same time, be reasonably sure that this solution is one of the best possible for any given process and set of constraints.

Time Assisted Analog Design
Pavan Hanumolu, University of Illinois, USA

Time-based signal processing is emerging as a viable alternative to analog signal processing traditionally performed in voltage, current, or charge domains. This tutorial discusses time-based techniques to implement classical analog functions such as filtering, control and data conversion. Time-based circuits using voltage controlled ring oscillators will be presented and their design tradeoffs will be elucidated with the aid of circuit design examples.

Gain Boosting & How to Judge OpAmp Settling Behaviour
Klaas Bult, Analog Design Consult, The Netherlands

Gain-Boosting is a means to enhance the gain of single-stage amplifiers beyond any limit, without degrading the amplifiers speed in terms of GBW or settling behaviour. This lecture discusses how to design a gain-boosting amplifier for optimal settling behaviour and also details the perfect way to judge OpAmp settling behaviour, showing any (start of) ringing (even at the lowest level) or slow settling components, applicable to any type of amplifier.

Design Mistakes You’d Rather Not Talk About
Klaas Bult, Analog Design Consult, The Netherlands

Every designer makes mistakes and mistakes are not the things we are proudest of, but they are the events that we learn from most. Unfortunately, they almost never get published as only succeses are accepted in Journals and Conferences. This lecture is talking about mistakes I’ve made – and learned from a lot, the hard way.

Continuous-Time Filters
Christian Enz, EPFL, Switzerland

Continuous-time filters play an important role in many communication systems and at the data conversion interface, where they are required for anti-aliasing and reconstruction. This module begins by reviewing the basic s-domain filter approximations and then looks into implementations strategies. We review active RC and gm-C topologies and study their imperfections and sensitivities to nonideal effects.