I recently attended the Texas Instruments 2018 Power Supply Design Seminar held in Phoenix, AZ. There were engineers from local companies from all around the Phoenix area in attendance that filled the hotel conference room. These engineers came to hone their power management design skills, many of them were not dedicated power designers, but engineers that needed to design their system power supplies.
There were about 35 or 40 attendees (I am not showing the back few rows in which I was sitting)
Bob Mammano’s Unitrode Company began these seminars in 1983, starting with SEM100 in 1983 and then when Texas Instruments acquired Unitrode in 1999, they continued this much needed tradition with SEM1300 in 1999. When I was a circuit designer in the 80s, I attended these Unitrode seminars every year. Later when I joined Texas Instruments, I participated in some of the early seminars in the early 2000s as a field application engineer. I really like the way that the annual seminar content changes with the industry and also has a diverse set of topics that greatly help designers. This year’s Power Management design content that I found most interesting was as follows:
1 Topic: Survey of Resonant Converter Topologies. My former TI colleague, Brian King presented this section.
What I liked: First, the classic resonant topology was shown and then we looked at the LLC Series Resonant Converter topology (LLC-SRC) and discussed Circuit linearization with a ½ bridge chock full of useful mathematic equations and graphs, which are generously used and discussed throughout this seminar. Soft-switching in a Resonant Topology was also discussed in depth with the input/output voltage gain using a sinusoidal input to the 2-Element and 3-Element L and C combinations showing the best and optimum L/C combinations of LCC and LLC passive components.
A classic LLC Series Resonant Converter (LLC-SRC) (Image courtesy of Texas Instruments)
2 Topic: Effects of Real Life Parasitics/Parameters.
What I liked: We looked at an ideal vs. a Real transformer with parasitics for the components like the L and C’s used, non-ideal switches, and finally, the benefits of Wide Bandgap Devices for a Resonant Converter.
3 Topic: Control and Design Challenges for Synchronous Rectifiers (SR)
What I liked: This was an extremely educational section with various SR control methods and design challenges with options in choosing the SR MOSFET and also operating in Continuous Conduction Mode (CCM), looking at noise optimization, bias, EMI and so much more.
4 Topic: Comparison of GaN and Silicon FET-based Active Clamp Flyback Converters.
What I liked: We analyzed adapter density and efficiency comparisons and also looked at passive and active clamp modes including Active Clamp Flyback (ACF) in a detailed analysis.
5 Topic: Power Solutions for Class D Audio Amplifiers.
What I liked: Crest Factor and Speaker Impedances were discussed. Audio degradation was analyzed and then we looked at the AC/DC Power Supply and an Automotive Power Supply for Audio design.
6 Topic: Common Mistakes in DC/DC Converters and How to Fix Them.
What I liked: This was one of the best sections. We were given 10 problems with graphs and equations and asked by the presenter to explain what was causing the particular problem and how we could fix the circuit.—This was so much fun and highly insightful and educational with some really neat subtle and intricate problems encountered in real circuit design.
7 Topic: Introduction—Loop Gain Overview
What I liked: This was perhaps the most insightful section for which most designers do not have an in-depth understanding. I learned a great deal from this section, especially how to properly measure Loop Gain in an Open-Loop setup. Actual bench setups were outlined in this section.
I will not give away all the details, but you can go to the seminar near you next year (I highly recommend that) and for now, if you missed this year’s seminar, you can visit the TI Power Supply Design Seminar—2018 Materials page and log in for the presentation materials and white papers. All engineers who need to design power supplies, especially those who are not expert power designers, need to have this material as well as the simulation software like TI’s Power Stage Designer and WEBENCH.