Designing Control Loops for Linear and Switching Power Supplies: a Tutorial Guide is now available for sale. This new book took me three years of work, every night. It first started in 2009, I wanted to write an exhaustive text on how to design compensators for power supplies. Operational amplifiers (op amps) were first on the list, but I then realized that there was many other types of active elements that could be used to perform this function: TL431, operational transconductance amplifiers (OTA) and shunt regulators like in the TOPSwitch (Power Integrations) series. If literature abounds on op amps, there are few documents on TL431, OTAs and TOPSwitches, but all scattered in application notes sometimes difficult to find. I have dedicated an entire chapter for each of them, even detailing TL431 internals. Of course, there are non-isolated and isolated versions with an optocoupler.
Please check the announcement in different languages (English, French, German, Japanese, Mandarin, Simplified Chinese, Korean and Spanish). Thanks to all my friends world-wide for their kind help! (Bernie, Werner, Ken-san, Kelvin, Patrick, W.S. and Juanito)
The copy just arrived in Hong-Kong Kelvin's office!
The book is now available in simplified Chinese and Korean. Thank you to Mr Zhangde Lu who translated the whole book in a record time! Mr Lu is a teacher in Shaoxing university in China.
The book is organized in eight chapters covering the following subjects:
Chapter 1: this chapter starts with the basics of dc-dc conversion, step by step with linear regulators used to derive essential formulas such as closed-loop impedances or closed-loop input rejection. Then the classical buck, boost, buck-boost are analyzed in CCM/DCM and critical modes until an input filter is added. There, you will discover the effects of the filter insertion and learn how to compensate the converter while still attenuating the input noise (95 pages).
Chapter 2: small-signal modeling is really an important topic if you want to be serious about power supply designs. The chapter starts by showing what State Space Averaging is all about and how complicated it can be. Then, the PWM switch model is introduced and three new versions are derived: auto-toggling DCM/CCM voltage-mode and current-mode models, with sub harmonic prediction in CCM for the later. Of course, these models are large-signal ones and operate in dc, ac and transient analysis. Finally, a borderline model is derived, later used in PFC stages. This 100-page chapter really explains how these models were derived and how to use them for your studies (146 pages).
Chapter 3: loop control is always hard to understand for some new comers. I've strived to make things look simple, explaining how the k factor was derived and showing that, sometimes, it is not a panacea. I propose different equations to let you manually select the poles and zeros, crossing over at the exact desired frequency. Also, in most of the books, only op amps are used to illustrate compensation. In this book, I derived the transfer functions of TL431-based type 2 and 3 compensators and I showed how the optocoupler pole can affect the phase margin (100 pages).
Chapter 4: this is where you will learn how to build your basic subcircuit blocks and how to construct your new models, if necessary. For instance, how to model the error amp of the UC384X family. Understand the differences between syntaxes and learn how to write in-line equations. A section specifically details the derivation of a magnetic model, based on non-linear junctions. See how to wire generic PWM models in various configurations for the best simulation speed. Learn how to extract physical data from a transformer to later pass them to a subcircuit (66 pages).
Chapter 5: in this chapter, we cover the design of dc-dc converters, the classical structures, in both voltage-mode and current mode configurations. There are small-signal analysis and transient studies in all cases The front-end filter section is also analyzed with input ripple specification targets (84 pages).
Chapter 6: rectifying the sinusoidal mains is a section common to all ac-dc converters. After all, the diode bridge and the capacitor are the elements that really perform the ac to dc conversion. The downstream converter is still a dc-dc, no? This chapter covers the classical diode bridge configuration then further introduces passive power factor correction, quickly followed by active power factor correction. The most popular topologies are covered and there are several design examples. An extensive usage of the average models is made here, leading to extremely short simulation times (88 pages).
Chapter 7: it is time to describe the isolated buck-boost also called the flyback converter. This chapter covers a lot of techniques pertinent to the flyback converter, what is the leakage inductor role, how it affects the drain voltage excursion and how you can use its presence in active clamp versions etc. The design section contains useful tricks to limit the converter power capability at high line for instance or to compensate the leakage spike on the auxiliary winding. There are three design examples, among which a multi-output borderline converter using the new BCM average model, also described in the book (160 pages).
Chapter 8: the forward converter is widely used in ATX power supplies (the so-called silver box) where the 2-switch configuration excels in 250 to 400-W applications. The chapter explores the various reset methods and introduces you to multi-output configurations through mag amps, or synchronous rectifiers. A complete design example is proposed at the end of the book (129 pages).
CDROM: the CDROM found with the book contains some of the most popular demonstration versions of currently available simulation softwares. I strived to give away almost all the examples of the book in OrCAD/PSpice and ICAPS/IsSpice formats. Some of the distributed versions also feature examples kindly translated by the software editors themselves. This is the case for uCap, TINA, Multisim, B2 Spice, 5Spice. Other demos include Power 4-5-6, Transim and TopSpice. I updated the Excel file dedicated to the k-factor to which TL431-based configurations have been added.
I purposely created specific application circuits that are not given away with the book. The library I am separately distributing includes the UC384X (UC3842/UC3843/UC3844/UC3845 SPICE models) precisely modeled and implemented in a lot of application examples. The same applies for Power Factor Correction circuits, ready to go on several platforms. The library and application circuits are available in different formats that are Micro Cap, TINA, OrCAD and IsSpice. You can download an application listing to check what is inside these libraries - also available for TINA and Micro Cap - OrCAD or IsSpice. Please drop me a line to my address to learn about this package and how to get it..
Feedback
Please, forgive me in advance in case you find errors, mistakes or typos, despite all the efforts in trapping them, there might still be some left, even further to thorough corrections ran by numerous reviewers. I have maintained a list of collected remarks, with credits to authors that have found them! The corrections file for the first edition is here, compiling all errors and mistakes previously published.
Reviews
The US IEEE Power Electronic Society has reviewed my book and published its comments in the PELS April newsletter.
Dr. Yan-Fei Liu from Queen's University (Canada) published a review in the Canadian section of IEEE.
