By Paul O’Shea, Senior Technical Editor

 

 

One of
the first things I did at APEC 2017 was have fun – I got to present an award to Steve
Tom, manager of GaN products at Texas Instruments for the LMG3410
GaN FET power stage
.

 

Texas Instruments PoY at APEC2017

 

Steve Tom, Manager of GaN products was
thrilled to accept the Electronic
Products Magazine
, Product of the Year award for his whole team, from EP Editor
Paul O’Shea.

 

 

 

Power Electronics Industry Collaborative
(PEIC)

 

 

PEIC_logo

 

The mission of PEIC is
to strengthen the US power electronics industry through a combination of
technology advancement, workforce development, and recommendations for
government policies to support this critical segment of the semiconductor
industry. The next major initiative planned for PEIC is to organize and present
a special session at the upcoming IEEE Energy Conversion
Congress & Exposition
(October 1 – 5, 2017 in Cincinnati). The focus of the session
will be on the unique workforce development challenges facing the power
electronics industry, and how to meet them, with participation by a
cross-section of PEIC members from component manufacturers, materials
suppliers, foundries, academia, and government labs.

 

Market
and regulatory conditions have created global demand for power electronics
systems that take advantage of new semiconductor technologies to enable higher
efficiency devices that operate at higher temperatures, higher frequencies, and
higher voltages in smaller packages and lower overall system cost. In order to
meet these demands at scale, several technological and manufacturing challenges
still need to be overcome. The PEIC group has a roadmap that provides an
overview of these challenges, the current state of the art, and emerging
solutions to achieve these benefits. Emphasis is placed on understanding trends
including inter-dependencies in semiconductors, capacitors, magnetics, and
packaging technology. Using this information, this roadmap also presents key
strategic recommendations for the U.S. to take advantage of these technological
trends.

 

Wide
bandgap (WBG) semiconductors such as silicon carbide (SiC) and gallium nitride
(GaN) offer the potential for smaller, more robust, higher power devices that
switch faster and are more energy efficient than silicon (Si) based devices.
The development of WBG semiconductor devices is a major component of the global
innovation race in power electronics. WBG semiconductor devices, especially SiC
and GaN-on-Si devices, are beginning to penetrate the market, although Si
devices continue to dominate the industry.

 

The US
WBG semiconductor device manufacturing supply chain is more developed in SiC
device technology, while GaN-on-Si devices tend to be manufactured in Asian
foundries, leveraging the massive Si device foundry infrastructure there.

 

Additionally,
next generation WBG semiconductors like bulk GaN and so-called ultra-wide
bandgap (UWBG) semiconductors like gallium oxide (Ga2O3),
aluminum gallium nitride (AlGaN) and diamond are in aggressive development as
they promise additional performance advantages over SiC and GaN-on-Si.

 

Semiconductors
are just one part of the overall power electronics system. While WBG and UWBG
semiconductors are capable of operating at higher voltages and temperatures,
today’s capacitors are not. Similarly, while WBG semiconductors are capable of
operating at higher frequencies, today’s soft magnetics are not. Additionally,
advances in packaging and thermal management are required before WBG
semiconductors can be fully leveraged. The implication of improved
semiconductor performance has ripple effects throughout the supply chain for
power electronics.

 

The components
that support the overall power electronics systems, including capacitors,
magnetic components, and packaging technologies are being pushed to match the
new semiconductor performance levels, which in turn is creating market
conundrums that are hampering growth of advanced semiconductors.

 

Current
capacitor technologies struggle to match the high temperature performance
needs, as existing capacitor technologies are limited by the properties of the
dielectric used. Consequently, this presents a global innovation whitespace for
the discovery and development of materials that exhibit the desired properties
with reliability and durability that can meet a variety of applications.

 

Ferrites
are the dominant form of soft magnetics used in power electronics systems
today, primarily due to their low cost. However, they are bulky and reducing
their size requires higher frequency operation, which causes high losses.
Amorphous alloys and nanocrystalline materials are being explored as potential
solutions to this issue, but none of the materials developed exhibit the
desired performance characteristics at a competitive cost yet.

 

New
packaging techniques and materials are being developed to improve the
performance of power electronics systems at high temperatures with improved
reliability over many thermal cycles. These innovations focus on two critical
areas of packaging, the die attach and the interconnection. In order to ensure
reliability at higher temperature, new die attach techniques and materials are
under development, including Silver-Tin alloy soldering, silver sintering, and
embedded packaging. Current interconnection methods are also prone to failure
and lose reliability at higher temperatures. New interconnection techniques are
under development, including ribbon bonding, ball bonding, and embedded
packaging.

 

The Complete Roadmap:

 

The
complete US Power Electronics Technology and Manufacturing Roadmap explores
these technology and market trends in detail and summarizes those trends in
easy to understand technology and manufacturing roadmaps. Key challenges to and
growth opportunities for the US supply chain are identified and a number of
detailed recommendations are made to close important gaps and to leverage
positions of strength, all aimed towards strengthening the domestic power
electronics ecosystem.

 

D3
Semiconductor

has been working under the radar for several years (since 2011), in development
since 2013, and is just now rolling out product. They have something very
unique that is based on listening to small to medium sized companies who have
trouble getting the support they need for their new designs. For example, many
design engineers need help with noise suppression for switching power supplies.
Enter the D3 Semiconductor +FET super
junction MOSFET that enables wafer-level configurability to aid with circuit
issues and provides hooks to offer mixed signal functions for more features. It
doesn’t end there. The company can offer new designs that can be ready for
reticle generation within hours. It also meets high temperature reverse bias
(HTRB) requirements of up to 4,000 hours. As you know, the HTRB test evaluates
long-term stability under high drain-source bias and is intended to accelerate
failure mechanisms. The device samples are stressed near the maximum rated
reverse breakdown voltage, usually to 1,000 hours, so 4,000 hours of this
stress test is significant. D3 says they have already retained global
e-commerce distributors and agents for through-hole, surface mount and advanced
surface mount products with availability from Q2-2017 (April) to Q4. This was
probably one of the more talked about introductions. The company says that the initial product lineup offer
high-performance superjunction MOSFETs that offer socket-for-socket
alternatives to competitive parts. You can find a product table showing the
initial +FET product line, at: http://www.d3semi.com/MOSFET-Overview.

D3 Semiconductor

 

The
long lead time associated with getting custom magnetics for the smaller
customer usually means these small sized customers are constrained to
off-the-shelf solutions. Because D3 allows these parameters to be specified
dynamically and addressed upfront, they can help customer get a custom junction
quickly. That means they can spin variances in hours and not days, and parts
done in days not weeks.

 

Some
observations
:

 

This is
an interesting step for silicon superjunction MOSFETs. However, compared to GaN
and some Si devices, it seems that the 77 nC Qg (gate charge) is somewhat high
(so that means more power loss). Additionally, the output capacitance (Coss)
and reverse recovery time (trr) are not mentioned, so high-frequency
performance can’t be assessed. Obviously, when compared to GaN power ICs they
don’t look as good because GaN enables efficiency increases to 500 kHz and 1 MHz
while offering a smaller size. Maybe we shouldn’t compare it to GaN but rather to
silicon MOSFETs to get a more accurate comparison.

 

 

Texas Instruments offered many new
products (as usual) so to get a good idea of what they featured they created a
video that provided a good video with a walk-through of their newest power
products. Your tour guide, Rich Nowakowski, provides you with a rundown of the TI
demos
that were presented at APEC 2017.

 

Of note, TI introduced the first end-to-end
high-frequency GaN power solution that includes:

 

  • 1
    kW totem pole PFC solution scalable to 3 kW with 99% efficiency and up to 4X
    the switching frequency of existing designs
  • 1
    MHz LLC isolated DC/DC stage delivering over 140 W/in3 of power
    density , or nearly 3X of today’s solutions
  • 300-A
    stackable single stage 48 V to POL DC/DC converter, eliminating intermediate
    bus (IBC) step and reducing the component count by more than 50%.

 

TI_APEC2017_converters

 

 

Also,
Bob Mammano introduced a new book: Fundamentals
of Power Supply Design, which provides information from power supply design
seminars;  ISBN: 978-0-9985994-0-3
.

 

This
book is just chock full of very useful information including chapters on
switching control algorithms, designing magnetic components, dealing with
electromagnetic noise, digital power control, and much more pertinent
information for power design engineers.

 

Excelsys

 

Excelsys
Technologies announced that its Xsolo power supplies at APEC. What makes them
special is that they are designed and tested to meet both the B and BF type
requirements per the IEC 60601 standard. Meeting these requirements makes
products suitable for applications that need to meet the performance for power
supplies used in medical applications. Excelsys’ testing procedures were performed
in accordance with requirements for B (body) and BF (body floating) medical end
products.
The goal of the testing was to
help manufacturers optimize their medical designs to achieve the highest
performance and safety levels, enabling first-pass success during agency
approvals.

 

Excelsys Xsolo Meets Medical Requirements

 

 

 

Excelsys meets medical requirements

 

By testing the
power supplies to the 60601 B and BF specification, the company helps
manufacturers with the task of certifying the end medical device as an applied
part for their intended applications, ensuring that customer’s product is safe.
It’s important because manufacturers often need to incorporate multiple power
supplies into a given system and still meet stringent requirements. To help
meet these requirements, Excelsys also offers low-leakage power supply
versions, which enable designers to incorporate multiple power supplies into
various medical-type rated systems.