DC-DC Converter Trends: A Special Report from Darnell Group

March 23, 2011 by Jeff Shepard

System makers are demanding more efficient products in smaller footprints at what is called "cost neutrality" levels. But the broad variety of applications across many diverse industries is allowing the dc-dc converter market to thrive in both traditional and niche segments. On-board solutions are eating away at the module market, yet "the brick is not dead." The following Special Report is based on the findings in Darnell Group’s latest 94-page analysis of this important market.

The reason both module and on-board (or "down") solutions will thrive is that power architectures are evolving beyond the classic distributed power model, adapting to system makers’ need for multiple voltage rails at lower voltages. Also, newer applications such as light-emitting diodes (LEDs) and dc building power require advanced components and materials to address unique operating environments. Yet many traditional applications remain, such as industrial and transportation that simply need proven, reliable products.

Underlying these trends are new packaging designs with increased integration. Smaller packages mean more thermal issues, and companies are looking at ways to improve efficiency while managing heat dissipation. The challenge for dc-dc converter module makers is how the Intermediate Bus Architecture is evolving: customers are demanding more efficiency, as well as configurability and optimization. This has led to a "Dynamic Bus Architecture," which consists of board-mounted dc-dc converters or point-of-load (POL) regulators that communicate with a centralized power system host control via a digital communications bus. The firmware is partly reconfigurable to specific applications, with "energy optimization algorithms" built in.

Most of the distributed power architectures being implemented today, and certainly future systems, include some form of digital power management and control. Digital power management has become a "given" in many systems, especially computer and communications applications. "Power supply designers" are becoming "system designers," and many of them also utilize digital control techniques when appropriate, rather than analog. The evolution of the Intermediate Bus Architecture (IBA) – from the Central Control Architecture (CCA) to the emerging Dynamic Bus Architecture (DBA) – is in part due to system demands that digital power management can address effectively.

The DBA makes use of a Digital Bus Converter (DBC), which is able to dynamically optimize its intrinsic efficiency, along with overall system efficiency, and can be controlled and monitored. In addition, the emergence of the DBC threatens to obsolete all of today’s analog bus converter products, including unregulated, semi-regulated and even regulated devices.

Although driven by obvious factors such as cost and efficiency, the real changes occurring in the dc-dc converter module and IC market are at the power architecture and advanced materials levels. The emergence of the Dynamic Bus Architecture (DBA) is, in fact, one of the most significant developments in the power supply industry in 10 years.

The DBA is already being designed into some high-end systems, and widespread adoption is expected in the next few years.

With global economies slowly recovering from the recession, companies are looking to keep costs low and optimize the equipment they already have. This means increasing efficiency across all application areas. Advanced materials, such as Silicon-carbide (SiC) and Gallium-nitride (GaN), are slowly becoming more cost-effective in applications with high temperature and high power requirements (SiC) or high-performance Information and Communication Technology (ICT) applications (GaN). As costs come down, these materials are likely to improve converter efficiencies and enable higher operating frequencies and smaller converter sizes.

As components and power architectures evolve, some new approaches could redefine the power supply landscape. The use of "on-chip" power supplies, for instance, includes the distribution of power in high-speed, high-complexity integrated circuits with power levels exceeding many tens of watts and power supplies below a volt. Intel has made gains with thin-film on-die magnetics that could speed mainstream adoption of this type of product. Power Supply on Chip (PwrSoC) is also making steady progress in the research and development area, although this technology is still several years away from commercialization.

Opportunities in the "Smart Grid" are still being defined, but most companies see smart meters as the "first step" in these applications. Some IC companies believe their product line is broad enough to encompass any smart-grid-related application, while other companies are adopting a "wait and see" attitude in terms of what will be successful.

Another trend that fits nicely with the Smart Grid concept is dc distribution in buildings, which is being embraced by utilities, where intelligent control allows communication with the utility. Dc power supports energy efficiency, "green" technologies, and building automation and control. Interest in dc building power is not new, but mainstream deployment has been elusive except in the telecommunications world. The energy demands of data centers renewed interest in dc powering, but the problems with batteries and legacy ac systems made such considerations daunting, particularly in North America and Europe.

"Dc-powered buildings" goes beyond data centers, however. The EMerge Alliance is an open industry association focused on low-voltage dc power distribution and its use in commercial interiors. In October, 2009, the EMerge Alliance released the EMerge

Alliance Standard, which "establishes a more efficient means of powering the rapidly increasing number of digital, dc-powered devices, such as sensors, lighting and IT equipment." Along with companies like Armstrong World Industries, the Alliance’s 70+ members include Delta and Tyco Electronics.

In addition, the EMerge Alliance announced the first set of 26 Registered Products in November, 2010. Already, companies like Armstrong World Industries, Cooper Industries, Finelite Inc., Lunera Lighting, Nextek Power Systems, Northwire Inc., and Tyco Electronics have products that have been registered for the EMerge Alliance Standard.

Standards are certainly driving changes in the dc-dc converter market. PMBus™ made its 2.1 specification for digital communications available to the public; the Distributed power Open Standards Alliance (DOSA) released its non-isolated MICRO converter standard; the PCI Industrial Computer Manufacturers Group (PICMG) has proposed formal improvements to the Advanced Telecom Computing Architecture (ATCA) standard for military, defense, medical, server and scientific applications; and Power-over-Ethernet (PoE) Plus now supports up to 30W per port, and depending on the powered interface, can be configured even beyond that.

The opportunities for dc-dc converter module and IC makers are greater now than they have been in years, due to emerging applications, new power architectures, advanced materials and components, and energy efficiency standards. The power supply industry can take advantage of these developments, knowing that additional markets are likely to arise in the future.

You’ll find detailed information on this 94-page analysis here.