ISSUE: September 2019


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» Novel Switched-Capacitor Converter Supports 48-V Power Architecture In Data Centers

» Using Mini E-Loads To Emulate Fast Slew Rates And High Peak Power Levels

» Secrets Of The Datasheet: What Rectifier Specs Really Mean

» Focus On Magnetics:
Waveform-Based Design: Key Parameters And Figures Of Merit For Power Circuit And Magnetics Optimization

» Spotlight On Safety & Compliance:
Explaining The ROI Of Compliance Efforts To Your Colleagues

» New Power Products

» Industry Events:
- NSREC 2019: Rad Hard Power IC Portfolios Add New Functions And Higher Performance Options
- EMC+SIPI Symposium Offered Practical Instruction, Latest Equipment And R&D
- Symposium Brings Together Long Island Power Electronics Community

» Other Top Power News

From the Editor's Desk

David G. Morrison
Editor, HOW2POWER TODAY       

Specialized power ICs don’t always garner the same publicity as those developed for high-volume applications. Sometimes the manufacturers don’t even announce the parts formally. Still, many of these specialty chips are technically interesting and important to the success of the targeted applications. Such is the case with many rad hard power components developed for space applications. With small satellites driving much product development, there are new power management functions available in rad hard versions, power chips offering higher performance than existing models, and more options for radiation immunity, packaging and cost. Although these product developments are not well publicized, industry forums such as the NSREC conference offer an opportunity to learn about the latest rad hard components, including the power ICs and modules. In one of this month’s Industry Events articles, I provide power component highlights from the NSREC 2019 expo. This issue also contains my report on the EMC+SIPI conference, which may be of interest to those following our many articles on designing power supplies for low EMI and EMC. More on EMC appears in the Safety & Compliance column, where the authors discuss strategy for getting your companies to “buy-in” to the idea of giving compliance requirements their due throughout the product development process. This issue also presents articles on a switched-capacitor converter topology for 48-V power architectures, miniature e-loads for testing transient performance of CPU voltage regulators and server power supplies, a guide to interpreting rectifier datasheets, an introduction to waveform-based design and more.


Novel Switched-Capacitor Converter Supports 48-V Power Architecture In Data Centers

by Rehan Tahir, Infineon Technologies Americas, Milpitas, Calif.

Adoption of 48-V main bus architectures is driving down operating costs for leading data center operators by reducing distribution losses by a factor of 16 compared to 12-V power delivery. The move to 48 V has triggered innovation in the design of board-level power supplies such as the zero-voltage-switching switched-capacitor converter, or ZSC, developed by Infineon. The ZSC topology is based on the Dickson charge pump; the voltage step down is achieved via capacitive energy transfer. This article describes the principles of operation of the ZSC and offers tips for successfully implementing this topology. Read the article…

The ZSC is a soft-switching converter
that uses loop parasitic inductance,
rather than physical inductors, to achieve
LC resonant operation. But it does
include a small inductor to support zero
voltage turn-on.

The microslammer power stage’s
small size and footprint allow it to
attach virtually anywhere in the dc
power delivery path.

Using Mini E-Loads To Emulate Fast Slew Rates And High Peak Power Levels

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

There are obstacles when using the existing test instruments to perform transient testing on VRs and server power supplies. The limiting factor in most low-voltage VR dynamic loading situations is the series inductance between the unit under test and the bulky electronic load (e-load). On the other hand, applying high current spikes to an ac-dc power supply output typically demands paralleling and synchronizing multiple e-load modules, which is not trivial. What’s needed is a miniature e-load capable of generating high-current slew rates and magnitudes. Such devices are known as slammers, or some variation on this name, and are available for purchase from vendors. You can also build these test tools to address your specific test needs and this article describes the design and operation of one I call a microslammer. This particular design addresses the need to test CPU power virus protection. Read the article…

Secrets Of The Datasheet: What Rectifier Specs Really Mean

by Jos van Loo, Taiwan Semiconductor Europe, Zorneding, Germany and Kevin Parmenter, Taiwan Semiconductor America, Chandler, Ariz.

Rectifiers are considered some of the easiest semiconductor components to design with. Their datasheets are not very complex. Nevertheless, in a lot of high-volume designs they can be highly stressed: they operate at very high junction temperatures and voltages. To minimize field returns and achieve zero defects, designers need a good understanding of rectifier manufacturing processes, test programs and statistics. Despite their simplicity, rectifier datasheets may puzzle modern designers. In this article, we will discuss the key specifications that designers, especially power supply designers, must consider when selecting rectifiers, and explain how semiconductor manufacturers test and then specify these parameters on their datasheets. This in turn leads to advice on how designers should interpret or apply this data. Read the article…

The derating of a rectifier’s
maximum forward current is
determined by the manufacturer’s
marketing department.

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

Waveform-Based Design: Key Parameters And Figures Of Merit For Power Circuit And Magnetics Optimization

by Dennis Feucht, Innovatia Laboratories, Cayo, Belize

Magnetics and power-converter design are related by common design variables that are electrical functions of time, or waveforms. This article offers a brief tutorial on waveforms commonly encountered in both magnetics and circuit design, their performance parameters, and why they are important in design optimization. While the author has used these waveform parameters and figures of merit throughout his writings on power circuits and magnetics, in this article, he takes a step back and defines these terms more methodically, while also noting where these terms come into use. Read the full story…

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

Explaining The ROI Of Compliance Efforts To Your Colleagues

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

In this column, we frequently stress the need to plan for compliance requirements—all types including safety, EMC, energy efficiency and environmental/restricted materials—early in the product design cycle or process. We stress the need to know the requirements and to perform pre-compliance testing as you go through the different design stages. But knowing we should do these things, and getting our companies to agree to do them are different things. So often there is resistance from other members of a design team, or other colleagues in the organization, to take the necessary extra steps to ensure that compliance needs are considered throughout product development. How do we overcome this resistance? A paper presented at the recent IEEE EMC + SIPI 2019 conference provides guidance on how compliance advocates can convince their colleagues in engineering and management of the value, or more specifically, the return on investment (ROI) of addressing compliance needs early and throughout the product design process. Read the full article…


Renesas Electronics’ ISL78714 Li-ion
battery management IC.

Battery Management IC Maximizes Cell Life And Driving Range For Hybrids And EVs

 Diagram: The battery management IC monitors and balances up to 14 series-connected cells with ±2-mV accuracy across automotive temperature ranges, letting system designers make informed decisions based on absolute voltage levels. According to the company, the ISL78714 provides the industry’s most accurate cell voltage measurements and safety features enabling ASIL D systems.

See the full story…

ABSOPULSE Electronics’ LQC 2K-3U2LC
liquid-cooled dc-dc converter.

Liquid Cooled, 600-V Input DC-DC Converter Delivers Up To 2000 W

 Photo: Measuring 5.2 x 5.8 x 15 in., the LQC 2K-3U2LC liquid-cooled dc-dc converter operates from a wide input voltage range of 400 V to 800 V, while generating a 24-V output at up to 80 A. Other output voltages are available on request.

See the full story…

ROHM’s BD83070GWL synchronous
buck-boost converter.

Buck-Boost Converter Extends Battery Life For IoT, Wearable, And Portable Devices

 Diagram: This synchronous buck-boost converter comes in a 1.2-mm x 1.6-mm WLCSP package suited for use in space-constrained applications.

 Graphs: The built-in low-on-resistance MOSFET and low control current circuitry achieve a power conversion efficiency of 97% during operation (at 200-mA load current) along with a 2.8-μA quiescent current consumption.

See the full story…

Power Integrations’ CAPZero-3
X-capacitor discharge ICs.

X-Capacitor Discharge ICs Enable Faster Discharge

 Diagram: The two-terminal X-capacitor discharge ICs block current flow through the X-capacitor discharge resistors when the ac voltage is connected, and automatically discharge X capacitors through those resistors when the ac is disconnected. When compared with previous-generation CAPZero chips, the CAPZero-3 devices allow faster discharge of X-capacitor energy.

See the full story…

More Power Products. . .

Accessory Brings Two-Port Shunt-Through Impedance Measurement To Scopes

Charger’s Low Termination Current Increases Battery Capacity

ICs Simplify USB Type-C Power Delivery, Enable HostFlexing And PDBalancing

Power Amplifier IC Delivers High Voltage And High Current


NSREC 2019: Rad Hard Power IC Portfolios Add New Functions And Higher Performance Options

by David G. Morrison, Editor,

The growth in space applications, especially small satellites, has been driving the development of space-grade power ICs and modules for several years. In response to demands for efficient power conversion solutions, semiconductor manufacturers and power module makers have continued to develop radiation hardened (rad hard) and radiation tolerant power supply ICs and discrete power semiconductors, point-of-load converters and isolated dc-dc converters. But they have also expanded their offerings of rad hard power management functions, such as the current limiters, load switches and load switch controllers exhibited at the recent NSREC 2019 conference in San Antonio. Visitors to the NSREC exhibition also saw the latest power converter reference designs, GaN power modules and power conversion building blocks that enable development of higher-performance rad hard power supply ASICs. Read the full story…

Load switches, GaN power modules
and IP blocks for power supply
ASICs were among the newest rad
hard power components on display
at NSREC 2019.

EMC+SIPI Symposium Offered Practical Instruction, Latest Equipment And R&D

by David G. Morrison, Editor,

EMC+SIPI is not your average IEEE conference. I discovered this while attending the most recent edition of the IEEE International Symposium On Electromagnetic Compatibility, Signal Integrity and Power Integrity, held July 22-26, 2019 in New Orleans. While this symposium included numerous papers on the designated topics, its greater emphasis seemed to be on providing professional instruction on these topics. Instead of allotting just a day or two for classes prior to the event, EMC + SIPI spread workshops and tutorials across three days of its five-day program. Some of the educational content was presented within the Clayton R. Paul Global University, which offered eight tutorials on broad topics. The instructive nature of the symposium even extended to the expo which showcased, all types of instrumentation, and electronic and mechanical equipment or accessories used in EMC testing plus software for modeling and analysis of EMC. Read the full story…

Symposium Brings Together Long Island Power Electronics Community

Now in its third year, the IEEE Long Island Power Electronics Symposium is a forum for all professionals involved in the use, design, qualification, test or manufacture of power supplies, power converters, power management, servos or energy storage. This event, which will be held on Thursday, November 7 from noon to 8:00 pm, is free for attendees but requires advanced registration. Attendees will receive admission to the exhibit floor, technical lectures, and complimentary networking lunch and dinner. The sold-out exhibit hall will be even larger than last year with over 43 displays. For more information and to register, see the website.


STMicroelectronics has been chosen by Renault-Nissan-Mitsubishi (Alliance) to supply high-efficiency SiC power electronics for advanced on-board chargers (OBCs) in its upcoming electric vehicles.

Paumanok Publications has released a study that addresses the 2019 world market for discrete inductors, beads and cores with 2020 forecasts and long-term forecasts to 2024.

The next CMSE, the Components for Military & Space Electronics Conference and Exhibition, will be held April 21 to 23, 2020 at the Four Points by Sheraton (LAX) in Los Angeles. CMSE focuses on the design, reliability, and application of electronic components for use in avionics aerospace, military & commercial space systems.

UNIPOWER, which manufactures high-efficiency rectifiers, battery chargers, inverters and complete ac-dc power systems, has added Frank DeLattre as executive vice president of sales..