ISSUE: September 2020


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» Using Forced-Frequency Resonant Zero-Voltage Switching In USB PD Adapters

» Using Local Energy Storage For Organized System Shutdown Simplifies Power Supply Hold-Up Time Requirements

» A Flexible Design For Fast Charging Supercapacitors In Industrial Applications

» New on
FAE Confidential

» Focus On Magnetics:
Why Magnetics Design Has Progressed So Slowly

» Spotlight On Safety & Compliance:
Keeping Up With IEC 62368

» New Power Products

» Industry Event:
- ECCE Plenaries Explore Battery Health Estimation, Hybrid/Electric Propulsion In Aviation And More

» Other Top Power News

From the Editor's Desk

David G. Morrison
Editor, HOW2POWER TODAY       

It’s been only a few years since power IC makers started introducing controllers and reference designs to address the versatile USB Power Delivery (PD) specification, which supports output voltages from 5 V to 20 V at up to 100 W. Now, as the application of USB PD continues to take hold in adapters, it’s driving the development of power supply ICs using innovative techniques to optimize performance. In this issue, an article by Jimmy Wang discusses the use of forced-frequency resonant zero voltage switching in DCM-operated flyback converters to enable more efficient, high frequency switching in USB PD-based adapters. This article highlights how a number of industry trends can come together to address the needs of high-volume power supply applications—high switching frequency, digital control, multiple operating modes and use of planar magnetics. All that’s missing is a GaN power switch, which we have seen in some other adapter designs. The standardization afforded by the USB PD spec and the associated Type C connector should give power IC developers plenty of incentive to keep crafting more intelligent and efficient power supply controllers for years to come. This issue also presents a feature on using local energy storage to ease bulk cap requirements in server power supplies, some application examples of supercapacitor fast charging, a look at factors that may be holding back progress in magnetics design, a review of IEC 62368, the latest power components and other news.


Using Forced-Frequency Resonant Zero-Voltage Switching In USB PD Adapters

by Jimmy Wang, Infineon Technologies, Shenzhen, China

Capable of supplying anything from 5 to 20 V and supporting power levels up to 100 W, USB-C cables may be the only thing we need to power our laptops, as well as to connect a wide range of peripherals to them. It also breaks the previous 7.5-W power limit at 5 V, opening up the possibility of charging smartphone batteries even faster. This article discusses some of the challenges in designing USB PD-based power adapters and how they can be addressed using a switching technique known as forced-frequency resonant zero voltage switching (ZVS) in a DCM-operated flyback topology. A reference design based on a controller developed to implement this technique, the XDPS21071, is presented, its principles of operation and other circuit details are explained, and a prototype and measurements of its efficiency are provided and discussed. Read the article…

The forced-frequency resonant form of ZVS
supports operation at frequencies above
100 kHz, enabling use of a planar
transformer embedded in the pc board.

As the percentage of total power
needing to be buffered is reduced
and the allowed voltage droop is
increased, the capacitor required for
secondary-side energy storage
becomes smaller than that required
for primary-side energy storage.

Using Local Energy Storage For Organized System Shutdown Simplifies Power Supply Hold-Up Time Requirements

by Viktor Vogman, Power Conversion Consulting, Olympia, Wash.

Traditionally, the energy needed for organized system shutdown is stored in the PSU bulk capacitor, which supplies power to the entire system during an ac fault event. When warning and/or hold-up time needs to be significantly extended (5 to 10 ms) for organized shutdown mode, a straightforward solution is to increase the PSU bulk cap size. But this greatly increases power supply size and cost, especially in server redundant subsystems using two or more PSU modules. This article studies an opportunity for easing the PSU hold-up time requirements for applications that require significantly extended warning time intervals. It shows how a local buffer cap can supply power just to the components critical to the organized system shutdown while increasing system immunity to indiscriminate power faults. Read the article…

A Flexible Design For Fast Charging Supercapacitors In Industrial Applications

by Nazzareno (Reno) Rossetti and John Woodward, Maxim Integrated, San Jose, Calif.

With their short charge and discharge cycles, supercapacitors require chargers that can handle high current. The chargers must work smoothly in constant current (CC) mode during a charge, which often starts at 0 V, and in constant voltage (CV) mode once the final output value is achieved. In high-voltage applications, many supercapacitors are connected in series, requiring chargers to manage high input and output voltage. In this article, the authors discuss two use cases for supercapacitors: automatic pallet shuttles in storage facilities and short-duration backup systems in fail-safe valve actuators. They then introduce a synchronous stepdown supercapacitor charger (the MAX17701) that can handle a large number of industrial and consumer applications, using the two use cases to demonstrate its capabilities. Read the article…

In the event of a power failure,
a string of 10 supercaps
delivers 10 A to power an


FAE Confidential

In FAE Confidential, we present the final installment in the series by the OT club: “The War On FAEs (Part 3): Management Shifts To Active Aggression.”

See FAE Confidential.

Sponsored by Payton Planar Magnetics
A monthly column presenting information on power magnetics design, products, or related technology

Why Magnetics Design Has Progressed So Slowly

by Dennis Feucht, Innovatia Laboratories, Cayo, Belize

This article contrasts the development of the magnetics industry, particularly power magnetics as applied in electronic power supplies, with that of the semiconductor industry by giving an overview of the history of each. The objective of this comparison is to analyze why the semiconductor electronics technology has grown so much quicker than the magnetics technology. Why have the theory, terminology and industry practices underlying power transformer and inductor design and development for power electronics failed to keep pace with that of power semiconductors and ICs, and semiconductors in general? Read the full article…

Sponsored by Power Integrations
A monthly column discussing standards and regulatory requirements affecting power electronics

Keeping Up With IEC 62368

by Kevin Parmenter, Chair, and James Spangler, Co-chair, PSMA Safety and Compliance Committee

The UL/EN/IEC 62368 standard is a merger of two standards—UL/EN/IEC 60065 Audio and Video Equipment and UL/EN/IEC 60950 Information and Communication Equipment. Most designers probably have some familiarity with 62368 because the industry has been transitioning to this standard for several years. There’s another regulatory milestone looming as the legacy standards in the European Union are about to be withdrawn on December 20, 2020. As this deadline approaches, many designers may still need to come up to speed on what the standard requires, and understand what variations of the standard are being applied as well as aspects of the standard that are still in flux. With that in mind, we present a brief overview and update on UL/EN/IEC 62368. Read the full article…

Vicor Header

Accelerating coral reef growth using renewable energy and Factorized Power

CCell Renewables, a marine engineering company, worked with Vicor to power their revolutionary reef growing system. The reef growing system relies on a power delivery network that can operate over wide-ranging and challenging conditions with a high degree of control and accuracy. CCell found Vicor’s Factorized Power Architecture (FPA) uniquely suited to manage the wide input voltage derived from renewable energy sources and deliver a required precise output voltage.

Read the case study!

More from Vicor:

Video: Why are power designs moving to 48V?

Webinar: Modular DC-DC system design done right

High powered LED applications: What’s the secret to delivering unparalleled performance?

NBM2317: Bidirectional power conversion between 48V and 12V



Payton America’s 10-kW planar

Planar Transformer Features 10-kV Partial Discharge Extinction Voltage

 Photo: Payton says its 10-kW planar transformer is the first high-voltage planar transformer with a partial discharge extinction voltage (<10 pC) of 10 kV between primary, secondary and core. Because partial discharges in a transformer deteriorate its insulation and can lead to failure of the transformer, they degrade its long-term reliability. By addressing this problem, the company can satisfy the demands of critical applications requiring 20+ years of operation.

See the full story…

Apogee Semiconductor’s TalRad
Process Design Kit.

Kit Speeds Design Of Rad Hard Power ICs And Other Mixed-Signal Chips

 Drawing: The TalRad Process Design Kit is a rad-hard process design methodology that improves the radiation performance of commercial IC process technologies, enabling much faster creation of rad-hard IC designs. This kit is implemented in TSI Semiconductors’ 180-nm CMOS high-voltage silicon process, which offers both a high level of integration and the high-voltage components needed for power design.

See the full story…

Dialog Semiconductor’s DA913X-A
dc-dc converters.

Highly Integrated Automotive-Grade Buck Converters Power In-Cabin Electronics

 Diagram: Designed to meet the increasing power and thermal efficiency requirements of in-cabin automotive electronics systems, these highly integrated single- and dual-channel buck converters deliver up to 10 A on a single output, or up to 5 A or 3 A on each of the dual outputs.

See the full story…

Magnetics’ updated Curve Fit
Equation tool.

Updated Curve Fit Equation Tool Eases Magnetics Design

 Screenshot: Equations in Magnetics’ Curve Fit Equation tool been updated to reflect performance improvements across multiple product lines including the new EQ and LP shape powder cores, the new Kool Mμ Hƒ and Edge powder core materials, and multiple new permeabilities.

See the full story…

More Power Products. . .

SiC Power Module And Gate Driver Kit Speeds Inverter Design

CMOS LED ICs Replace Legacy Bipolar Drivers

Low-ESR, Low-Cost Supercapacitors Offer Values Up To 600 F

Latest Generation 200-V GaN FETs Double The Performance


ECCE Plenaries Explore Battery Health Estimation, Hybrid/Electric Propulsion In Aviation And More

ECCE 2020 has announced the speakers for its virtual plenary session on October 12. This session will feature talks on “The price of degradation—The value of prognostics—Opportunities and Needs in Battery Health Estimation,” “NASA Aeronautics Strategies for Hybrid/Electric Propulsion and Transforming Aviation,” “Current and Future Outlook of Hydrogen Fuel Cell on Multiple Market Sectors,” and “System Operations—Defenders of the Grid—Past, Present, Future”. For more about these talks and the distinguished speakers who will be giving them, see the conference website.


Dialog Semiconductor has expanded its collaboration with Renesas, introducing power management solutions for the R-Car M3 and R-Car E3 automotive computing platforms. The Renesas products can now be integrated with the DA9063-A system PMIC and DA9224-A sub PMIC.

Performance Motion Devices (PMD) has received the Medical Device ISO 13485:2016 certification, making it one of the first companies in the motion control industry to do so, according to PMD.

UnitedSiC, a manufacturer of SiC power semiconductors has entered into a distribution agreement with Macnica, a distributor of semiconductor products in Japan.