HOW2POWER TODAY

ISSUE: September 2021

To ensure receipt of future issues, please add david@how2power.com to your address book. Visit how2power.com

IN THIS ISSUE:

» Integrated GaN Power Stages Enable High-Performance 48-V To 12-V Power Converters

» Smart Gate Driver IC Simplifies Motor Drive Design In Battery-Powered Applications

» Designing An Open-Source Power Inverter (Part 2): Waveshape Selection

» Focus On Magnetics:
Transformer Winding Design: Bundle Layer Approximation As Rings

» Industry Event:
Free, Virtual ECCE 2021 Expo Presents Latest Tools, Instruments And Components

» Spotlight On Safety & Compliance:
A Standalone Controller Eases Compliance With USB PD Standards

» New Power Products

» Other Top Power News

The IEEE Energy Conversion Congress & Exposition (ECCE) provides a forum for discussion of power electronics in a system-oriented context. A quick way to get a sense of this perspective for ECCE 2021, which will be held October 11-15, is by browsing the list of special sessions where you’ll see topics such as power electronics in renewables and power electronics on the grid, for example. But that type of application focus is only part of the picture, because as the other session titles suggest, there are also discussions of the closely related fields such as electric machines, which figure heavily in the conference’s overall technical program, energy storage, and even peripheral topics like cybersecurity. This system context is why they call it the energy conversion congress. Naturally, there are also special sessions on the underlying enabling technologies such as wide-bandgap devices but even these tend to be discussed in a system context such as vehicle electrification. This system context can also been seen in the tutorials. Although originally planned as a hybrid event, the conference has shifted to a fully virtual format due to ongoing Covid-related travel restrictions. For those who have not yet attended, the virtual format provides another convenient opportunity to participate. Click here to see the different options available to register. One of these options is a free registration to attend the virtual exhibition, which is previewed in this issue. The ECCE expo offers a chance not only to see the latest design tools, test instruments, and components, but also a convenient chance to ask the vendors’ experts questions on technical issues. Attend during live exhibit hours (10-11 and 10-12) for the chance to interact directly with the exhibitors or take advantage of the exhibition’s 30-day access to view vendor resources at your convenience.

HOW2POWER EXCLUSIVE DESIGN ARTICLES

Integrated GaN Power Stages Enable High-Performance 48-V To 12-V Power Converters

by Ron Vinsant, uPI Semiconductor, Mountain View, Calif.

GaN devices are finding use in an increasing number of applications. To address these applications, uPI is introducing a family of integrated GaN power stages that combine two 100-V GaN FETs in a half-bridge configuration with a dual-channel driver and protection features. These devices simplify the development of GaN-based designs by eliminating the difficulties associated with driving enhancement-mode GaN FETs. In this article, the application of a uPI GaN power stage is demonstrated in a 48-V to 12-V, 180-W synchronous buck converter. This design example showcases the efficiency, thermal and switching performance made possible by the GaN device, while discussing elements of the design, like cooling and inductor choice, that affect converter performance. A low-cost technique for measuring the GaN device’s fast switching transitions is also described. Read the article…

The nonisolated synchronous buck
converter represents the simplest
implementation of a 48-V to 12-V
converter, but the GaN power stages can
also be applied in other topologies.

In a circular BLDC inverter board,
like that used in a cordless drill,
much of the PCB area is taken up by
the six MOSFETs, which does not
leave much room for the controller,
gate drive and associated functions.

Smart Gate Driver IC Simplifies Motor Drive Design In Battery-Powered Applications

by Peter Green, Infineon Technologies, El Segundo, Calif.

The design of power-dense motor drive inverters is highly challenging, requiring many components to be placed on an often awkwardly shaped board within a confined space. At the same time, many different functions and protection schemes are necessary to produce a robust system. This article discusses how the high level of integration provided by the 6EDL7141, a smart gate driver IC for three-phase, battery-powered BLDC motor drive inverters, addresses the space limitations encountered in cordless power tools, which operate from battery packs in the 12-V to 48-V range, and similar battery-powered applications. It also explains key details of the design process when implementing motor drive inverters using this IC. Read the article…

Designing An Open-Source Power Inverter (Part 2): Waveshape Selection

by Dennis Feucht, Innovatia Laboratories, Cayo, Belize

Part 1 of this series discussed the need for an open-source kilowatt-level inverter design and outlined a power architecture for such a design. Besides enabling a more serviceable, maintainable product, the proposed Volksinverter enables many improvements in the performance and functionality of what’s typically provided by low-cost power inverters marketed to consumers. Here in part 2, we delve further into system design issues, explaining how battery choices influence the selection of electrical specifications for the inverter, including its power protection features. Then we step back and review some mathematics relating to inverter-produced waveshapes, which will help us later in optimizing inverter design to meet various design goals. But first, we’ll note the similarity between inverters and another power supply function, which will help us to understand the origins of certain inverter design equations. Read the article…

Battery-sourced inverters perform
the inverse function of a PFC rectifier
input of battery chargers. Many of
their circuit equations are identical,
with input and output variables exchanged.

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

Transformer Winding Design: Bundle Layer Approximation As Rings

by Dennis Feucht, Innovatia Laboratories, Cayo, Belize

Wire bundles consist of strands of individual wire conductors bound together and wound as turns in a winding of a magnetic component such as a transformer. Having less than five strands minimizes the proximity effect within a bundle when twisted. Some bundles have many more than five strands, and within the bundle, those strands form the same kind of pattern as wire wound in layers in a winding, with the same packing properties. With multiple layers of strands within a bundle, the proximity effect becomes significant. To estimate what it might be from Dowell’s equation (or algebraic approximations of it) some estimate of the number of layers of strands, M_s, within the bundle is needed. This article derives various formulas for estimating M_s and gives rationales for them. Read the full article…

INDUSTRY EVENT

Free, Virtual ECCE 2021 Expo Presents Latest Tools, Instruments And Components

by David G. Morrison, Editor, How2Power.com

Each year, the IEEE Energy Conversion Congress & Expo hosts an exhibition that showcases the latest design tools (hardware and software), test instruments and components that are critical to the development of the various energy conversion applications that are discussed at ECCE. This year’s ECCE exhibition is being hosted virtually on the vFairs platform, which will make the exhibits accessible to a global audience of engineers, who can browse the booths and interact with exhibitors for free. This article previews some of the products that companies will be showing in the virtual ECCE expo, including current sensors, magnetic cores and planar magnetics, GaN devices, LED drivers, and automotive power MOSFETs. Meanwhile in the design tools and instruments area, we highlight products for hardware-in-the-loop testing, simulation and design tools for power electronics and motor drives, a new oscilloscope series, and programmable power supplies. Several of these products will be featured in interesting demos. Read the full story…

SPOTLIGHT ON SAFETY & COMPLIANCE       
A monthly column discussing standards and regulatory requirements affecting power electronics

A Standalone Controller Eases Compliance With USB PD Standards

by Samantha Morehead and Sagar Khare, Maxim Integrated, San Jose, Calif.

USB Power Delivery (PD) poses new power requirement challenges because of the variety of voltage and current combinations available—5 V, 9 V, 15 V, 20 V, 28 V, 36 V, 48 V and 1.5 A, 3 A, and 5 A, etc.—to supply the wide range of power levels the USB PD standard can provide. The power source and the inline devices communicate their power capabilities and power needs, respectively, in proper voltage and current levels before the source provides power over the USB cable. Some solutions require multiple ICs, including port detectors, microcontrollers and chargers for power delivery. While these solutions work, they take up space on a board, increase the solution cost, and require custom firmware, which can be time-consuming to create. A standalone PD controller can help address these challenges by managing the power negotiations without firmware development. Read the full article…

  — POWER PRODUCTS IN 3 IMAGES OR LESS

OTHER TOP POWER NEWS

Infineon Technologies and Panasonic have signed an agreement for the joint development and production of the second generation of their GaN technology.

Amber Solutions has secured four new patents for digital management of GFCI, AFCI and overcurrent/inrush current protection in solid-state circuit breakers and other electrical products.