The Art of Electronics: The X-Chapters – Reviewed

The Art of Electronics: The x-Chapters by Paul Horowitz and Winfield Hill (Cambridge, 2020) is a companion volume to the popular The Art of Electronics (3rd edition, Cambridge, 2015) by the same authors. Announced in the main volume, the x-Chapters have been ever since eagerly expected both in among industry professionals and hobbyists.

After placing a pre-order for the book in July 2019 and finally getting it to my hands in January 2020, I have now spent a good 4 months with the volume. Although this time is too short to study the book from cover to cover, I thought it is enough to share my thoughts on it.

In short: The x-Chapters is a great addition to the main volume and reasonably priced. If you have spent a lot of time with the original, I recommend getting the x-Chapters: the content is of high quality, and most of it will be relevant to you sooner or later. If, on the other hand, you don’t yet have the original, I recommend getting it first.

The content

So, what do you exactly get between the iconically styled black-and-gold covers? Shortly put, you get 506 pages worth of high-quality content on the same topics as in the main volume, but with an emphasis on slightly more advanced or detailed issues.

There has been some confusion on what to expect from the book: is it an appendix, sequel, or a collection of footnotes?

In the book itself, the authors spell out the name as “eXtra Chapters”. Formally, the book is indeed structured as additional chapters to the original work. However, the chapter themes and numbering mirror that in the original, so to me, the x-chapters are easier understood as extensions of the original chapters by extra sections.

The extended chapters, with a brief description, are:

1x Real-World Passive Components: more content on resistors, capacitors, inductors and diodes, also relays and switches. Wires introduced!

2x Advanced BJT topics: detailed bipolar junction transistor behaviour and advanced applications

3x Advanced FET topics: detailed FET behaviour and advanced applications; emphasis on MOSFETs, high voltages

4x Advanced Topics in Operational Amplifiers: detailed analyses of op amp behaviour; a truly diverse but useful collection

9x Advanced Topics in Power Control: additional topics in power regulation and conversion. Again, a diverse but useful collection.

Although only five of the 15 original chapters have been extended, the additions are very substantial: on average, the chapters have received around 100 pages each. In fact, Chapter 9x is almost as long as Chapter 9 in the original, Chapter 2x just as long, and Chapters 1x, 3x and 4x longer than the originals by tens of pages!

The titles of the chapters reflect the nature of the added content: the topics relegated to the additional volume are, for the most part, more advanced or specialist than the ones in the main volume. Moreover, looking at the Table of Contents, instead of the structured, or even pedagogical, procession of themes in the main volume, in the x-Chapters one finds a long sequence of disconnected sections under a common heading.

Two things follow from this. First, the average reader is not likely to find all of the content relevant, or even understandable, without a prior dedicated study of the topic. Second, the x-Chapters is not a standalone book, and makes sense mainly after reading and in the context of the main volume. Although most sections could stand as very interesting and useful articles, as a book the work leans against the main volume.

However, this is exactly what the authors intended – they admit as much in the introduction, and repeat the message in the opening of each x-chapter.

And as a collection of additions to the main work, the x-Chapters is excellent. All of what you liked in the AoE itself (if you did) is there:

  • the informative and succinct text;
  • the same flawless typography and exceptional graphical quality;
  • a multitude of data-rich figures, totalling 681 (!), more than one per page on average;
  • and the immensely useful tables (24 of them) you will return to for the tenth, the hundredth, or for some of us, the thousandth time;

all of which are delivered in the familiar clear and natural style.

The topics are indeed more advanced than in the main volume, but not so much that they would be irrelevant for the average worker in electronics. Whether it is for hobby or occupation, if you are involved in circuit design for a number of years, I bet you will find most of the sections topical sooner or later.

My user experience

After 4 months of getting familiar with the book, I have personally found most use of Chapter 1x. The very first figure in the book – the current carrying capacity of wires – has seen almost daily use. I have also many times referred to the figures and discussion in Sections 1x.2, 1x.3 and 1x.7 to check capacitor tempcos, diode leakage currents and other realities of life in circuit design. On receiving the volume in January, I also immediately had to see what Horowitz and Hill had to say about connectors this time. Indeed, the content in this chapter is so essential in practical design of electronic systems that it could have in my mind fitted well into the main volume.

By contrast, Chapters 2x and 3x, both on transistor behavior and applications, are still pretty much untouched in my copy. While the content appears interesting, it goes beyond my understanding and interest, at least for now, as I always try to get away with ICs of the highest possible level integration. That said, if you habitually build your own amplifiers, for example, you will certainly benefit from the material.

Chapter 4, advanced operational amplifier treatment, has in my opinion somewhat wider appeal than the previous two. As a measurement engineer, I have found the unity-gain buffer and RRIO sections (4x.4, 4x.11) already very useful; “bullet-proofing” amplifier inputs, as demonstrated in 4x.16, is an example of something I have not done, but probably should be doing.

The final chapter receiving extension, Chapter 9x, is similar to Chapter 1x in being more practically oriented. The finger test of component temperature, for example, is both useful and amusing at once, and is followed by fine and condensed review or more accurate temperature measurements. The chapter also contains very interesting discussion of myths of PWM in powering DC motors and the dangers of fake mobile phone chargers.

Although I have only scratched the surface, I am certain that in the coming decades of work and hobby in electronics I will eventually go through most of the sections.


But is it worth the money? At slightly above $40 or 40 EUR, the x-Chapters is not exactly cheap – not at least as an extension to an existing work. Per page, it is somewhat more expensive than the main volume both in the US ($0.08 vs. $0.07/p) and in Europe (0.09 vs. 0.05 EUR/p) at the time of writing.

But compared to the average university textbook or a professional handbook, for example, the x-Chapters is not expensive at all; as a student or an engineer, you will mostly have to pay more than double the price for something far worse written and laid out.

Personally, I consider the main volume The Art of Electronics (3rd ed.) one of the best bang-for-the-buck books out there. Although the value proposition in the x-Chapters is not quite as stunning, it is still well worth the money.

Should you get it now?

It depends. I would break the question down to user cases:

Should you get the x-Chapters …

… if you have owned a copy of The Art of Electronics (3rd ed.) for some time and are eager to read more?

Definitely yes. If you continue working within electronics, you are likely to benefit enough from the volume in the long run.

if you are new to electronics and want to read up?

No – I think it is better first to get only the main volume. If you are anything like the average learner, an overabundance of information right at the outset is not conductive of understanding, and it is better to start without an additional 500 pages.

… if you have read the The Art of Electronics (3rd ed.) but do not like the style?

I would at least consider. Personally, I would buy the x-Chapters just for the figures and tables. If you have found them useful in the main volume, I would consider getting this book.