Digital Power Unleashed

Green Plug Exhibits at Embedded Technology 2010 and British Embassy

Sharing exhibit space with Green Plug partner, Imagination Technologies, and Toumaz, Greenplug met with many visitors to discuss our upcoming Green Power Processor and technologies aimed at bringing the next generation of power supply control to the market. The three day Embedded Technology 2010 show in Yokohama, Japan was well attended.  http://www.jasa.or.jp/et/ET2010/english/index.html

 

 

 

The following week, British Ambassador, David Warren, and Imagination Technologies CEO, Hossein Yassaie, welcomed a select group of business and technology leaders to present innovative products to the press and leading Japanese companies.  Green Plug is honored to be invited to this prestigious event.  At the event, we met with executives that showed keen interest and enthusiasm in the Green Power Process.

 

Come visit with Green Plug at CES 2011 in Las Vegas to learn more.  Happy Holidays.  http://archive.constantcontact.com/fs052/1101775948184/archive/1103998948181.html 

The Green Power Processor

Sometimes it takes a bolt of lightning to get a fire burning.

At Green Plug, that lightning bolt has been our partnership with Imagination Technologies, one of the world’s top 10 System-on-Chip (SoC) IP providers.  Choosing the META embedded processor from Imagination for our Green Power Processor (GPP) chip has enabled us to build a  cost-effective platform and rapidly bring our power control technology to market.  Ultimately, DC power hubs enabled with the GPP chip will be capable of simultaneously powering multiple electronic devices, each with its own specific voltage and power requirements.

So what sparked Imagination’s interest in Green Plug and why is it so critical to the future of the universal power movement?

Imagination recognized that today’s power supplies, which use analog circuits for feedback control, will not meet future demands for more efficient and Smart Grid-capable power adaptors, and that these analog power supply designs soon will be replaced by more flexible digital controllers.  Enabled by these new digital controllers, consumer and environment-friendly multi-port power hubs will generate a huge market opportunity for their META processor core and replace billions of today’s single-use power adapters. Imagination’s System-on-Chip development skills and Green Plug’s power system architecture leadership is a winning combination to develop advanced power conversion solutions for the new generation of energy-aware consumers.

Add in the leadership and deep chip technology background of innovator and Imagination CEO Hossein Yassaie, who recently joined our Board of Directors, and you’ve got the kind of powerful partnership needed to enable digital, universal, green power for every consumer electronic device on the planet.

Universal Power Movements Around the World

Now that USB has provided for universal power access to most electronic products that consume 10W of power and less, we're starting to see standardization efforts for higher power devices take hold around the world.  Green Plug applauds the industry-lead efforts on standardizing DC power adapters so that they can power virtually any device.  IEC 100_1699 (http://www.iec.ch/cgi-bin/procgi.pl/www/iecwww.p?wwwlang=E&wwwprog=vote2.p&progdb=db1&wcom=100&wclass=&wdoc=1699&wsup=) and IEEE 1823 Universal Power Adapters for Mobile Devices (http://grouper.ieee.org/groups/msc/upamd/) are two such examples of the standardization efforts underway.

Green Plug will follow this activity closely and expects to continue to play a key role in the evolution of universal power.  In addition to interoperability, Green Plug envisions power adapters will evolve from a consumable to a consumer durable item with much more functionality.  In addition, we expect smart power hubs to provide gateway access to the Smart Grid so that many, many more electronic devices in the home and office can participate in the demand-response, load-control services in the Smart Grid.

We welcome your opinions.  Please post comments and visit http://iwantmygreenplug.com.

Easier Green Plug Implementation Options

Green Plug-enabled smart power adapters communicate with compatible electronic products so that all of them are able to power any device, regardless of voltage needs.  Our Greentalk^TM power protocol and Greenwire^TM multi-function physical layer let power supplies dynamically adapt to use patterns, saving energy.  The technology also reduces solid waste by allowing consumers to keep these smart power adapters and battery chargers for use with future products long after their current products have become obsolete.

What's New

Part of our technology (the Green Load Processor – GLP) exists on the product side and is licensed free of charge to strategic adopters.  The GLP offers a wide range of implementation choices that can be done for little or even no added BOM cost as a compilable macro for an existing chip in the product. 

Imagination Technologies, a leading provider of System-on-Chip (SoC) intellectual property (IP), is the first manufacturer to make Greentalk and Greenwire available in its core products.  That means any vendor that uses chips based upon the Imagination SoC can easily turn on the Green Plug functionality in its products without adding any parts or cost..  Green Plug makes money by selling a Green Power Processor (GPP) chip that provides power supply control and communication.  Vendors will sell smart power adapters using the GPP as a paid-for option to customers wanting to have a more functional, eco-friendly power solution for their electronic products.  Consumers will have the choice of getting the conventional power adapter at no charge or paying a premium for a better power adapter or smart power hub.

Green Plug is talking with several popular chip companies that make chips that go inside many electronic products about incorporating the free product-side IP into their chips.  This will give vendors even more choices for turning on the Green Plug functionality without adding new components or increasing BOM costs.

 

Get Ready for a Power Revolution

We couldn't be more pleased to see the progress being made in the efforts towards wireless power as described in the "Wired" article: http://www.wired.com/gadgetlab/2009/02/wireless-charge.

Green Plug promotes the benefits of a new power model that include:

• Reducing power cord clutter since each power supply can power multiple devices concurrently
• Reducing standby power drain, which can be significant when you replace 4 or 8 individual power adapters with a single smart power hub
• Providing unprecedented convenience - never worry about finding the right charger for a specific device or about forgetting your laptop charger (anyone will work when devices can negotiate power with power sources)
• Reducing toxic waste caused by the disposal of billions of device-specific power adapters (interoperability means power adapters will be used again and again.)

Wireless power solutions hold the potential for even further reductions in power cord clutter.  But powerful, efficient solutions may still be off in the future for laptops, televisions, printers and similar products.  We can take a major step towards the wireless power solution today by making consumer electronic products able to accept power from any power source whether it be wireless or wired.  That way, power hubs can be developed that offer both wired and wireless power ports.

It is unlikely that every home and office electronic device will be equipped to receive wireless power.  But, just as many wireless routers also integrate wired (Ethernet) connections, we think that a wireless power mat with a few integrated universal wired power connectors provides the ultimate in convenience and interoperability.

We'd like to hear from you.  Please share your thoughts on this topic.

The Digital Power Wave

Hello:

This month's blog is brief, containing a link to an event on trends towards the use of digital power controllers.  Please take a look at: http://digitalpower.darnell.com.

Last month, our CTO blogged about innovations in the power supply industry due to the use of digital controllers.  At DPF '09, you'll learn about techniques for adaptive control and learning systems.  At Green Plug, we're happy to see smart power supplies gaining momentum, with an estimated 5 billion units shipped by 2010. 

Digitally controlled power adapters have all the necessary components to support the open systems power interface that Green Plug advocates.  The availability of these smart power adapters will make it possible for vendors to provide dynamic output power configuration and build new power monitoring applications without adding hardware costs and will enable vendors to provide the kind of interoperability that consumers crave.

Digital control circuits for power supplies are coming

   By Gus Pabon, CTO

    Since about 1973, power supply controllers have been analog and not much has changed in their basic functionality, until recently.  An emerging trend is happening where digital power supply control IC’s are starting to make their way into designs and they show a huge potential for additional benefits that can be brought to power conversion electronics.

    In today’s analog technology one approach for regulation and control of the output DC-voltage is achieved using a voltage-feedback method that compares the DC-output voltage that is proportional to a reference voltage that is part of this feedback loop; in this part of the electronics, additional circuitry is used to compensate for amplifier gains over adequate frequency ranges to ensure stability of the output voltage.   The difference between these two voltages is then used to set the limit when compared to a voltage ramp generated internally by the control IC;  this difference-voltage and the voltage ramp are inputs to a comparator circuit whose output results in a square-wave of voltage with a varying duty-cycle.  This duty-cycle-varying square wave drives the power switches in the power supply.  By this method, regulation of the constant DC-output voltage is achieved even under conditions where the power supply loading changes.

    Now, with the emergence of high-speed digital electronics, this feedback-loop can be implemented in a digital form.  The output voltage can be fed to an Analog-to-Digital (A/D) converter whose output is compared in digital (multi-bit) form to a digital-reference.   The difference is then fed in its digital form to some type of Digital-Signal-Processor (DSP) as part of the digital-control circuitry.  This DSP , among its many functions, performs compensation to ensure stability of the feedback loop and hence the output voltage.   The output of this DSP is then fed to Duty-cycle registers that output (as in the old analog-control method) a square-wave of voltage with a varying duty-cycle that is used to drive the power-switches in the power supply.

    If the basic functionality described above was all that was required in the operation of a switch-mode power supply, digital-control would be at best equal to the mature analog solutions.    It is in the digital circuit’s ability to dynamically change its operating mode where a digital controller shines and outperforms an analog controller.   A simple example considers the stability of the feedback loop over a wide operating range of the power supply’s output current; each current load of the power supply determines an operating point.   In the analog method, the feedback loop is optimized (compensated) for stability for only a few discrete operating points and outside of these operating points there still exists stability, but the operation of the feedback loop is not at its optimum point.  The reason for this is that the stability of the feedback loop in an analog system is achieved by using discrete-components (capacitors, resistors) that set the frequency-dependent gain of an amplifier.   As these components are fixed in their values, the compensation and hence the performance of the feedback loop is fixed.

    In a digital system, simple monitoring of aspects of the power supply’s operation (such as output current loading) can be fed to the digital-controller and the digital-controller can employ firmware that can digitally change the compensation depending virtually on any operating point of the power supply and ensure close-to-optimum operation of the feedback loop.  This is possible because only firmware and not discrete circuit-components determine the compensation of the feedback loop.

    Other clear benefits of digital control are that accurate and reliable communication is enabled with a digital-controller.  Such communication with the “external” world can be bi-directional.   This communication enables the power supply to be configured from an external source by receiving communication or by the power supply sending information, enabling a single power supply to be used for many applications – to achieve universal, interoperable behavior.   Communication also enables monitoring of the power delivered by the power supply or the “state-of-health” of the power supply and its components, and is readily available to any host system chartered with overseeing the power system.

    Also, every power supply has additional “house-keeping” circuitry whose function is usually for protection and prevention of catastrophic failures;   this is additional analog circuitry that adds cost, requires pcb real-estate both of which are not desirable and also as the protection-thresholds are set using discrete circuit components they are not easily modified.   In a digital-controller, much of this protection function can be done in firmware thereby eliminating additional circuitry and as describe above the protection-thresholds can be easily and dynamically (on the fly) changed in firmware.

    Today digital-controllers are two to three times the cost of their analog counter parts, but as our demands for power-converters increase as is happening due to trends in rechargeable battery systems, solar-arrays, electric cars, etc.,  so will the complexity in their designs.  This increasing complexity in applications will soon be hard-pressed to be met by analog controllers.   When this point of inflection is reached, higher volumes of digital-controllers will drastically drive the prices down, resulting in cost-competitive solutions.   The trend toward digital control in power conversion is only in its infancy and the potential of the benefits it brings to a power electronics designer are sure to be welcomed as a breath of fresh air.

The significance of the GSMA announcement

I read a very interesting article (http://www.popsci.com/gear-amp-gadgets/article/2009-03/universal-phone-charger-so-what-0#comment-33540) on the significance of the GSMA decision to adopt USB power for cell phone devices.  The major benefit comes not from the standardization on the cell phone-side power connector, but on the choice to require a USB power adapter with a USB-A connector.

Because the USB power adapter has a universal connector, you can use just one power adapter to power a variety of products, simply by changing the cable.  For example, I use my iPhone power adapter (designed by our CTO) to power my iPhone, Bluetooth headset and digital camera.  When I get a new phone, Bluetooth headset or digital camera, I won't need or want a new power adapter.  USB power adapters will be commonplace and we won't throw them away when we buy new 5V products.

The hard problem is to provide the same level of interoperability to non-5V products.  What's needed is a means of dynamically configuring the power adapter output to match the power needed by any device connected to it.  When we do this, we will significantly reduce eWaste from unnecessary power adapters that get thrown away simply because they are designed to work with just one product.  Consumers will enjoy the interoperability.  The environment will be spared a signficant waste.  Vendors will not be required to give away power adapters that work with just one product.  Everyone wins.

Would they do it?

If CE product vendors could wave a magic wand to eliminate the need for an external power adapter for so many of their products, would they do it?  If there were a way for notebook PCs, cordless phones, printers, digital picture frames, wireless routers and other products to get power without the need of an AC-DC power adapter, would the product vendors benefit?

Like the Myth Busters, we'd like to get to the bottom of the myth that product vendors want power to be non-interoperable.  We'd like to hear from you about your thoughts on whether vendors enjoy benefit from or suffer unnecessary costs because of the lack of interoperable DC power solutions.

That last iPod I bought is compelling evidence to me that vendors benefit from universal power; the iPod doesn't come with a power adapter.  If you want one, you have to pay extra for it.  This is good both for vendors and consumers, because USB power is commonplace.  I didn't buy a power adapter for my iPod; I already had 3 or 4 USB power adapters that work with my iPod and many other USB-powered products.  But Apple didn't have to give me one at its expense, either.

We invite product vendors to comment on the net gain or loss they have due to the fact that today, there are no interoperable power interfaces for non-USB-powered devices.

There is a magic wand that we can wave to fix the problem.  But, it will take a few years for it to be waved completely.  We can get to a place where power is universal and smart power outlets are commonplace.  The cost to enable devices to accept power from smart power outlets is negligible in comparison to the costs reduced in dealing with product-specific power adapters.

One challenge for product vendors is that the savings from the elimination of the product-specific power adapter happens later, even though small costs are incurred immediately.  I've reviewed several economic models that all show the payback is significant and substantial, even accounting for the mismatch in timeline.

All viewpoints are welcome.

Fig. 1:  Embedded costs of power adapters.

There Are AC Power Strips; Why Aren't There DC Power Strips?

Today, I looked under the desk in my den and I saw two AC power strips and one UPS with multiple AC power outlets.  Then, I noticed that only two devices in my office did not have an external AC-DC adapter - my desk lamp and the UPS itself.  But, 11 power bricks and wall-warts - each capable of powering just one device - are plugged into the many AC power outlets supplied by the AC power strips and UPS.

Something is very strange about all this.  I have had the AC power strips for years and years.  But the power bricks and wall-warts come and go so frequently.  How many cell phones, laptop PCs, printers and cordless phones have I had over my 20-year career?  Could it be that my AC power strips have been faithfully serving me for so long?  And, if so, why is DC power so different?

Two things are obvious to me about the role of AC power strips:

1. One device serves multiple products
2. Any device can get power from any AC power outlet.

AC power is interoperable, because (at least on a country-wide basis) it has a fixed voltage.  Our DC-powered products, however, use 5V, 6.5V, 7.5V, 9V, 10.5V, 12V, 14.4V, 16V, 18V, 19V, 21V and other voltages.  They're all different.  Attempts to standard on voltages have failed, because different products optimally work with different voltages. 

One way to deal with the many different voltages that DC-powered products require is to enable power supplies to negotiate the necessary voltage and current levels with the DC-powered products.  Green Plug developed a power communication model that enables any powered device to dynamically negotiate power with the power adapter it is plugged into.

Once the communication link has been made, an unlimited number of power monitoring and control applications are possible.  For example, power adapters can dynamically adjust their output to adapt to changing conditions such as being powered off or having reached full battery charge.  Also, a single AC-DC power adapter can serve power to multiple DC powered devices.

So, instead of throwing away 200+ DC power bricks and wall-warts like I have these past 20 years, I could have used just 2 or 3 multi-port DC power hubs.  Product vendors would not have had to bear the cost of designing, packaging, shipping and giving me the power adapters with the products I purchased.  My wife and I would have had less clutter in our den.  And, the environment would be much better off.

Isn't it time for DC power strips that can dynamically adapt to the power needs of anything that plugs into it?