The AMP group is the first power consortium that offers interoperability to ensure seamless use between products

President and CEO, Murata Power Solutions; MARK ADAMS, Sr. VP, CUI; and
BOB CANTRELL, Sr. Applications Engineer
Ericsson Power Modules

Products magazine recently talked with a few members of the Architects of
Modern Power (AMP) group to discuss what is new with digital power. As you
know, the aim of the alliance is to create the most technically advanced,
end-to-end distributed power solutions for a complete ecosystem of hardware,
software, and support.

: The AMP Group was created at the end
of 2014, but why did you feel that it was important to create a new standards
organization for digital power? Wasn’t this the intent of PMBus?

: The development of PMBus has been an
important standard for the power community. In fact, the use of PMBus has
become ubiquitous within the power space for digitally controlled products such
as front-end power supplies. While PMBus defines a communication protocol, it
does little to define the exact performance of a given device.

: The intent of the PMBus specification
was to create a language that everyone could understand, but it’s how that
language is interpreted that can cause issues. The AMP Group offers something
new — it takes a sub-segment of PMBus and defines it within the group, so we
are still PMBus-compatible, but we’ve taken the translation of the language and
made it uniform across each AMP standard.

EP: So you would say that one of the key selling points for
the AMP Group is the ability to reliably second-source products that have true
plug-and-play capability, but how compatible is the alternative source?

: This is one of the primary reasons
for the formation of the AMP Group. The AMP Group is the first power consortium
that offers true interoperability. This is hugely significant considering the
complexity of these designs. Currently, we are working on even more ways to
ensure seamless use between products that meet the standards that we will be
announcing in the coming year.

EP: The fact that CUI, Murata, and Ericsson are based in different
regions of the globe must have an impact on how the group works, though?

Adams: It does, but we’d see it as a significant advantage. It
helps to make us unique in our approach both globally and from a customer-base
standpoint. Being spread out globally allows us to have a broader perspective
to apply to the vision of the AMP Group and our roadmap. Between us, we have
insight across a range of customer bases, from tier 1 to a start-up level.
Every customer has individual needs, and so by collating the global market
information from CUI, Ericsson, and Murata, as well as the tier information
from our joint customer base, we are able to better position ourselves to
respond to the concerns of the market and our customers.

EP: The AMP Group talks a lot about the traditional growth
areas for digital power, such as communications. What are the other areas that you
are forecasting for growth in this market over the coming years?

Cantrell: Today, devices to power Information and Communications
Technology (ICT) comprise the majority of digital power units shipped;
additionally, digital power products should be well positioned to power the
IoT. Digital power is capable of providing real-time monitoring and control of
key parameters, which will allow the most efficient power conversion to be
realized. Digital power products offer numerous advantages, even in
applications in which monitoring is not necessary; for example, where there is
no PMBus or I2C
bus, etc. “Dumb” digital products typically offer a flatter efficiency curve
and higher efficiencies at low loads. They have far fewer components; thus,
their sizes are typically smaller than comparably rated analog power products
and, because they contain fewer components, they intrinsically have higher

markets include: electric vehicles, the railway industry, a broad range of
industrial applications, and smart homes, to name a few.

EP: Talk us through software-defined power (SDP) and its
importance and why it should be on our radar moving forward. For which markets
is this especially relevant?

Pimpis: There are two aspects to SDP. The first item is the
hardware solution. The hardware portion is application agnostic and, therefore,
able to be used in almost any computing or instrumentation device. Only the
output voltage range and the maximum output current of each device limit the
hardware. The second aspect is the software solution: The software allows
individualized performance monitoring of the hardware to provide customized
control over the range of the application. It is the software that identifies
the unique performance envelope of the hardware and ultimately makes the
hardware performance unique to the end application.

EP: What impacts are cloud computing and the IoT having on
power infrastructure? How does the AMP Group envision tackling the power
demands of data centers?

There will be trillions of sensors used in the IoT, which, paired with the
desire of today’s consumer to have all of their data residing on the cloud and
able to be accessed immediately from any device anywhere, means that cloud
computing and the IoT are having a tremendous impact on power infrastructure —
putting it under a significant amount of stress (Fig. 1). On top of this, you have things like video-on-demand,
in which the throughput and storage capabilities to make this happen are
massive and all of this data has to be backed up. We supply data centers in our
other product areas, but power is their biggest concern — data centers have the
same problems that our other customers have at the board level, so this is a
challenge across the spectrum.


1: Cisco predicts that 50 billion “things” connected to the internet will have
an exponential effect on the volume of data consumed.

Data-center servers require high-performance computer boards that can present
challenges to designers who are seeking to maximize data-processing and storage
capabilities without compromising on space. On occasions, upwards of 40 power
rails can be required, which leads to more point-of-load (POL) converters, all
powered by intermediate bus converters (IBCs), in turn fed by an ac/dc
front-end power supply (Fig. 2).
We frequently see multiple power rails being used to power a single IC, which
needs to be powered up and down in a specific sequence in order to prevent
damage to the IC. This necessary sequencing involves routing signals to
communicate the status of the different power supplies. The AMP Group has
simplified the design-in and interchangeability of digital power modules by
standardizing the behavior of digital power modules in response to PMBus


2. Multiple POL converters on the system board are required due to the
proliferation of supply rails at the board level.

EP: The AMP Group has predominantly focused on isolated 48-V
to 12-V and non-isolated standards. What other areas is the group focusing on
for the future?

We are always talking to our customers about what they need us to be focused
on, as individual companies and as a group. Our aim with future enhancements is
to help the system designer reduce time-to-market for new designs as well as
tuning the power rails to achieve optimum efficiency. We’re also planning to
offer AMP ac/dc converters, which would be something that no other consortium
has attempted.


3: Standards for five POL power converters from 6-A to 120-A capacities and
three advanced-bus converter standards from 264 W to 1 kW have been defined by
the AMP Group.