**46954 – Accuracy Improvement of the Analog Integrated Circuits**

**February 26-28/2023, 9:00 a.m.**

Auditorium 1003, Meyer Bld

**Dr. Vadim Ivanov, Texas Instruments**

Instructor: |
Vadim Ivanov |

Teaching assistant: |
Itamar Melamed |

Lectures: |
13 hours, 3 days |

Academic points: |
1pts |

Exam: |
TBD |

Course Fee : |
1700$ (See membership options) |

***Registration is open until February 20, 2023**

**Course Content:**

In 1951 Bernard Tellegen proved that set of an ideal amplifier, reference, limiter, and RC network

is functionally sufficient for the implementation of any analog functions. It has started a neverending quest to design ideal amplifiers and references. The most accurate voltage references use

the bandgap voltage of the silicon. Out of many options, the de facto standard of an ideal amplifier

is an operational amplifier. Operational amplifiers and bandgap voltage references have been the

first analog ICs in production (since the 1960-s), now with >20,000 types of such ICs available

from almost every semiconductor company and enjoying multi-billion sales just for stand-alone

ICs.

This course will start with an overview of the analog design methodology based on feedback

control of every important parameter in the system. While every feedback loop may be unstable,

we will demonstrate ways to verify and guarantee the stability of the resulting multiloop system.

This methodology will be illustrated with multiple non-trivial examples of current mirrors with

unmeasurable high output impedance; transconductors with wide input range, any load-stable

LDOs with instant load regulation.

Based on this methodology, we will proceed with the in-depth design of the bandgap voltage

references in different processes and for different applications. We will consider embedded

references in digital systems, references for the highest state-of-the-art accuracy, and references

with nanopower consumption. In addition to the circuit design and tradeoffs between

noise/consumption/settling time, we will discuss the challenges with testing, trimming, and

packaging.

The next part of the course is dedicated to improving all OpAmp parameters. These include

speed-to-power ratio, noise, CMRR and PSRR, and input and output voltage range. We will

consider offset and offset temperature drift trimming as well as structures and circuits for offset

elimination by auto-zeroing and chopping.

**Topics per Day:**

**Day 1 (4 academic hours):** **Structural design methodology and **

**practical frequency compensation**

Discussed are the rules of generating circuit solutions with desired analog functionality out of an

immense variety of options. Design starts with a graphic presentation of the problem with signal

flow graphs or block diagrams, then changing it to the form where everything necessary is

controlled with a dedicated feedback loop, and, finally, implementing the structure using an

elementary cell library. The resulting circuit comprises multiple feedback loops. Interaction

between these loops makes frequency compensation of such a system non-trivial task,

unsupported by the general control theory. Every MOS or bipolar transistor is nonlinear, which

may cause conditional stability and complicated compensation.

We will consider system structure design for stability, and additional elementary circuit cells to

the textbook set, resulting in achieving 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.

**Day 2 morning (2 academic hours): Bandgap voltage references**

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.

**Day 2 afternoon and Day 3 (7 academic hours): Operational amplifier**

**speed, accuracy, and consumption improvement**

Discussed are circuit techniques to improve all essential parameters of the Operational Amplifiers.

Most circuit techniques shown have been previously published only in patents and applications.

Examples include input stage design for low offset, noise, unmeasurable PSRR and CMRR, input

common-mode voltage range; ways of improvement OpAmp speed to power ratio; open loop

gain; power supply range both in high- and low-voltage amplifiers; improving offset by a packagelevel trimming, auto-zero, and chopping; achieving high capacitive drive capability; current limit,

temperature protection, POR.

26FEB23 | 1 | 09:00 ~ 09:50 | Course Introduction, |

2 | 10:00 ~ 10:50 | Structural design methodology | |

3 | 11:00 ~ 12:00 | Structural design methodology | |

4 | 12:00 ~ 13:00 | Lunch Break | |

5 | 13:00 ~ 13:50 | Practical frequency compensation | |

6 | 14:00 ~ 15:15 | Practical frequency compensation | |

7 | 15:30 ~ 17:00 | Practical frequency compensation | |

8 | 17:10 ~ 18:00 | Q&A | |

27FEB23 | 1 | 09:00 ~ 09:50 | Bandgap voltage references |

2 | 10:00 ~ 10:50 | Bandgap voltage references | |

3 | 11:00 ~ 12:00 | Bandgap voltage references | |

4 | 12:00 ~ 13:00 | Lunch Break | |

5 | 13:00 ~ 13:50 | Operational amplifier speed, accuracy and consumption improvement | |

6 | 14:00 ~ 15:15 | Operational amplifier speed, accuracy and consumption improvement | |

7 | 15:30 ~ 17:00 | Operational amplifier speed, accuracy and consumption improvement | |

8 | 17:10 ~ 18:00 | Q&A | |

28FEB23 | 1 | 09:00 ~ 09:50 | Operational amplifier speed, accuracy and consumption improvement |

2 | 10:00 ~ 10:50 | Operational amplifier speed, accuracy and consumption improvement | |

3 | 11:00 ~ 12:00 | Operational amplifier speed, accuracy and consumption improvement | |

4 | 12:00 ~ 13:00 | Lunch Break | |

5 | 13:00 ~ 13:50 | Operational amplifier speed, accuracy and consumption improvement | |

6 | 14:00 ~ 15:15 | Operational amplifier speed, accuracy and consumption improvement | |

7 | 15:30 ~ 17:00 | Q&A | |

8 | 17:10 ~ 18:00 | Exam |

**Prerequisites:**

044137 Electronic Circuits

**Recommended prerequisites:**

046187 Analog Circuits Design

**Grading:**

Written exam – 100%

**Instructor’s Bio:**

MSEE 1980, Ph.D. 1987, both in the USSR. Designed electronic

systems and ASICs for naval navigation equipment from 1980 to

1991 in St. Petersburg, Russia and mixed signal ASICs for sensors,

GPS/GLONASS receivers and for motor control between 1991 and

1995.

Joined Burr Brown, now Texas Instruments, Tucson, in 1996, where

worked on the operational, instrumentation, power amplifiers,

references and switching and linear voltage regulators, and where

he is currently the Operational Amplifier Technologist. Has 126 patents, with more pending, on

analog circuit techniques and authored > 30 technical papers and three books: “Power Integrated

Amplifiers” (Leningrad, Rumb, 1987), “Analog system design using ASICs” (Leningrad, Rumb,

1988), both in Russian, and “Operational Amplifier Speed and Accuracy Improvement”, Springer,

2004

***Registration is open until February 12, 2023**