EPC Technical Articles

Rethinking Server Power Architecture in a Post-Silicon World

The demand for information in our society is growing at an unprecedented rate. With emerging technologies, such as cloud computing and the Internet of Things, this trend for more and faster access to information is showing no signs of slowing. What makes the transfer of information at high rates of speed possible are racks and racks of servers, mostly located in centralized data.

Alex Lidow, Ph.D., David Reusch, Ph.D., and John Glaser, Ph.D.
March, 2016
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Material Miracles

Silicon, the stuff upon which the Valley was built, is maxing out. The future, according to some, belongs to gallium nitride. What is it, and what does it mean?

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What is GaN?

The cost of electrical power is a key driver of socioeconomic vitality, as it enables us to improve our quality of life and advance new applications and industries. GaN (gallium nitride) has emerged as a displacement technology to the venerable, but aged, silicon solutions that will allow us to stay ahead of our demand for more and more efficient power.

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Single Amplifier for a Multi-mode Capable Wireless Power System

The proliferation of wireless power products and multitude of wireless power standards for mobile applications is leading to consumer confusion and hindering adoption. This article discuss a multi-mode capable amplifier topology capable of operation at both high (6.78 MHz) and low (100 kHz – 315 kHz) frequencies.

By: Michael de Rooij, Ph.D.
EEWeb – Wireless & RF Magazine
August, 2015
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Scientists are developing an x-ray pill you can swallow

A new product being developed might make checking for colon cancer as easy as swallowing a pill. The technology is based on a new type of chip from EPC that uses gallium nitride instead of the traditional silicon. CEO Alex Lidow told Quartz that his company’s chips can withstand the high voltage needed by the sensors inside the Check Cap.

July 30, 2015
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How To GaN: Paralleling High Speed eGaN FETS for High Current Applications

This column evaluated the ability to parallel eGaN® FETs for higher output current applications by addressing the challenges facing paralleling high speed, low parasitic devices, and demonstrated an improved paralleling technique. For experimental verification of this design method, four parallel half bridges in an optimized layout were operated as a 48 V to 12 V, 480 W, 300 kHz, 40 A buck converter, and achieved efficiencies above 96.5%, from 35% to 100% load. The design method achieved superior electrical and thermal performance compared to conventional paralleling methods and demonstrated that high speed GaN devices can be effectively paralleled for higher current operation.

By: Alex Lidow
April, 2014

EPC's Michael de Rooij presents Wireless Power Transfer demonstration at APEC

EPC's Michael de Rooij presenting the Wireless Power Transfer demonstration for Alix Paultre, editor, Power Systems Design magazine.

Power Systems Design
March, 2014
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How To GaN: eGaN® FETS in High Performance Class-D Audio Amplifiers

The quality of sound reproduced by an audio amplifier, measured by critical performance parameters such as THD (Total Harmonic Distortion), damping factor (DF), and T-IMD (Inter-modulation Distortion), is influenced by the characteristics of the switching transistors used. Class-D audio amplifiers typically use power MOSFETs, however, lower conduction losses, faster switching speed, and zero reverse recovery losses provided by enhancement-mode GaN (eGaN) FETs enable a significant increase in the sonic quality, and higher efficiency that can eliminate heatsinks. The result is a system with better sound quality in a smaller form factor that can be built at a lower cost.

By: Alex Lidow
February, 2014

GaN — Still Crushing Silicon One Application at a Time

Enhancement-mode gallium nitride transistors have been commercially available for over four years and have infiltrated many applications previously monopolized by the aging silicon power MOSFET. There are many benefits derived from the latest generation eGaN® FETs in new emerging applications such as highly resonant wireless power transfer, RF envelope tracking, and class-D audio. This article will examine the rapidly evolving trend of conversion from power MOSFETs to gallium nitride transistors in these new applications.

Power Pulse
By: Alex Lidow
February, 2014

How To GaN: eGaN®FETs for High Frequency Wireless Power Transfer

A highly resonant, loosely coupled, 6.78 MHz ISM band wireless power transfer will be presented that show how eGaN FETs are enabling this technology. This column will show efficient wireless energy transfer using current eGaN FETs, and present examples of a voltage mode class D and class E approach.

By: Alex Lidow
January, 2014

GaN – Crushing Silicon One Application at a Time

Enhancement mode gallium nitride transistors have been commercially available for over four years and have infiltrated many applications previously monopolized by the aging silicon power MOSFET.

Power Pulse
By: Alex Lidow
October, 2013

How To GaN: eGaN FETs in High Frequency Buck Converters

In this installment the optimum layout will be implemented in a high frequency buck converter yielding greater than 96% efficiency switching at 1 MHz.

By: Alex Lidow
September, 2013

How to GaN: Driving eGaN FETs and Layout Considerations

The previous columns in this series discussed the benefits of eGaN(r) FETs and their potential to achieve higher efficiencies and higher switching speeds than possible with silicon MOSFETs. This installment will discuss driver and layout considerations to improve the performance achievable with eGaN FETs.

By: Alex Lidow
August, 2013

eGaN FET-Silicon Power Shoot-Out: A Retrospective of Sixteen Articles

When a new technology is introduced, it is not reasonable to think that engineers will intuitively know how to effectively and efficiently take advantage of the performance enhancements that the new technology offers – there is always a learning curve. This is being borne out in the case of the rapidly emerging technology of high performance gallium nitride transistors.

GaN FET technology was made available to the general power conversion engineering community in mid-2010 when Efficient Power Conversion (EPC) introduced the industry’s first commercially available GaN transistor. Since that time, EPC has continued on two parallel paths – one to expand their portfolio of products and the other to share what it learns about the use of the technology with power conversion systems design engineers. One of these educational efforts has been to work with the editors of Power Electronics magazine and publish a bi-monthly series of articles on the characteristics of GaN technology and its applications.

This series is entitled eGaN FET -- Power Silicon Shoot Out. Articles in the series took on both basic issues and specific applications using gallium nitride components. It is timely to make a quick review of the sixteen articles to make certain that we have accomplished the goal of assisting engineers in climbing the learning curve. This retrospective look will give us insight into what further topics and studies are needed to advance the adoption of GaN technology, the need to learn is never finished.

By: JOHAN STRYDOM, Ph. D., Vice President, Applications, Efficient Power Conversion Corporation
MICHAEL DE ROOIJ, Ph.D., Executive Director of Applications Engineering, Efficient Power Conversion Corporation
DAVID REUSCH, PH.D., Director, Applications, Efficient Power Conversion Corporation

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How To GaN: Enhancement Mode GaN Transistor Electrical Characteristics

For a power system designer who has worked with a power MOSFET, upgrading to an enhancement mode GaN transistor is straightforward. The basic operating characteristics are quite similar and yet there are a few characteristics that need to be considered in an efficient design in order to extract the maximum benefit from this new generation device. EEWeb By: Alex Lidow July, 2013 More ...

Delivering Efficient Power Conversion with Package-Free HEMTs

Packaging has its downsides: It increases the footprint and the price of a power MOSFET, while degrading its performance through unwanted increases in resistance and inductance. The best solution is to ditch the package, a step that allows GaN HEMTs to be cost-competitive with silicon incumbents, argues Alex Lidow from Efficient Power Conversion Corporation.

Compound Semiconductor
June, 2013

How To GaN: Introduction to Gallium Nitride (GaN) Transistor Technology

The first installment in a new monthly column by Alex Lidow, CEO of EPC, introduces the concept that GaN-on-silicon power devices could be a superior replacement for the aging power MOSFET.

By: Alex Lidow
June, 2013

eGaN FET-Silicon Power Shoot-Out Volume 14, Part 1: eGaN FET Small Signal RF Performance

Even though the eGaN FET was designed and optimized as a power-switching device, it also exhibits good RF characteristics. This article, the first of a two-part series on RF performance, focuses on RF characterization in the frequency range of 200 MHz through 2.5 GHz.

By: Michael de Rooij, Ph.D., Executive Director of Applications Engineering, Efficient Power Conversion
Johan Strydom, Ph.D., Vice President of Applications, Efficient Power Conversion
Matthew Meiller, President, Peak Gain Wireless

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Exploring gallium nitride technology

It has been three years since the commercialization of gallium nitride (GaN) devices as MOSFET replacements in a commercial DC-DC application. With the emergence of GaN devices, coupled with now attainable applications previously not achievable with MOSFET-based FETs, a favorable stage has been set for GaN-device developers to release emerging application potential largely unimagined and untapped.

EETimes Asia
May 16, 2013

Highly Resonant Wireless Power Transfer System Teardown

This article is an overview of the elements needed to assemble a wireless power transfer system. The EPC9104 demonstration system from EPC showcases the high frequency, voltage, and power required for efficient wireless power transfer.

EDN Europe
March 2013