Until recently, there has been no standard, commonly accepted definition of “digital power management” or “digital control.” The confusion isn’t helped by the fact that digital, analog and “hybrid” solutions are often included in these definitions. In Darnell Group’s recent digital power electronics report, five “levels” of digital power management and control were proposed (see Figure 1).
At this stage of commercial development, Board Management, Converter Management and Power Conversion are being implemented. Although “facility monitoring” capabilities already exist, such as Emerson Network Power’s systems, they don’t connect from the Facility Management level to the Rack Management level. This will be dependent on the other three levels coming more into commercial play.
Using this model, it is appropriate for forecasting purposes to discuss an “integrated circuit (IC) functional equivalent market,” rather than identifying a “digital IC unit market.” Digital ICs often incorporate more than one function into their design. Taking into account this difference, the worldwide digital IC functional equivalent market includes non-Voltage Regulator (non-VR) loop controllers, VR loop controllers, power factor correction (PFC) loop controllers, converter management ICs and system management ICs.
Looking at absolute chip costs for analog and digital (on a silicon-to-silicon basis), the decline in prices for digital is expected to “cross over” with analog prices around 2008, with digital chips being cheaper than analog chips after that point. Digital is currently less expensive than analog if “multiple function” solutions are required for specific applications. By 2008, companies will no longer need to sell digital solutions based on features that make them more cost-effective than analog solutions.
The VR controller market is already large and well-established. Excluding these products, and using the pricing assumption discussed above, the remaining segments are expected to grow from $42 million in 2006 to $633 million in 2011, a compound annual growth rate of 72%. In 2006, the majority of these sales will be converter functional equivalent ICs, but by 2011, sales of non-VR controller functional ICs will slightly exceed converter sales.
The digital standards landscape has been active over the past year or so, with both the Z-Alliance and PMBus™ actively competing and promoting products. One of the key issues that digital standards could address, from a system level, is how well the various components integrate and operate from the top level down. It is problematic to address the interoperability of the hardware at the converter and semiconductor levels across different suppliers.
Of concern to some power supply and component makers are the proprietary approaches taken by system makers that make it hard to ensure interoperability. An OEM can define a product as “standard” to its operations, and it can create a specification for a power supply or dc-dc converter for its own use and require multiple suppliers to provide products to that specification. Regardless, if every system OEM has its own protocol, there is no opportunity for IC makers to make standard product ICs that can lower costs, development time and risk.
With the market for digital power management and control heating up, however, system makers could be getting a jump on power supply manufacturers, particularly in the area of data center energy efficiency. IBM recently announced that it is “committed to optimizing the data center environment” with its PowerExecutive and Calibrated Vectored Cooling technologies. Other system makers are also introducing their own digital power technologies or working with groups to increase energy efficiency. IBM, Hewlett-Packard, Sun, Dell and Tyan are working with AMD to utilize AMD’s Optimized Power Management (OPM) technology for the Opteron processor. The Green Grid Alliance was founded in April, 2006, and includes companies such as AMD, HP, IBM, Dell, American Power Conversion and VMware. AMD officials have indicated that the Green Grid Alliance will address data center power consumption and cooling issues.
General agreement exists that multiple sourcing is essential for the successful commercialization of digital power management and control products. Power-One created the Z-One Digital Power Alliance to offer second sourcing. And in April, 2006, Primarion and Linear Technology Corp. announced an alliance to produce digital Point-of-Load (POL) products for the networking, computing and telecommunications infrastructure markets.
Other trends could help push or delay the adoption of digital control in power supplies. Product development and design are moving targets, and emerging (and more expensive) solutions can get pre-empted by new designs of existing products. For example, a potential threat to the adoption of digitally controlled power supplies in the telecommunications market is multiple output (e.g. five or more), embedded dc-dc converters for telecom applications, such as DSLAMs. These produce lower output power levels (50W-150W per board), and eliminate the need for an intermediate bus architecture (IBA).
“Module-chip” packaging is another potential threat to digital. In October, 2005, Linear Technology introduced a new line of high-density power modules, the LTM4600 µModule. This product is not digital, but it has some programmable capabilities, and some analysts believe this product could compete head-on with other digital solutions.
In general, digital is expected to find the best opportunities in higher-wattage applications, but not necessarily all higher-end applications. Non-isolated dc-dc POLs and embedded ac-dc power supplies are currently considered the two best potential markets for digital control. For ac-dc power supplies, some companies see 250W and up as the “sweet spot” for digital; for dc-dc converters, 150W and up. Due to the increased use of digital PFC, embedded ac-dc is considered one of the better opportunities.
Along with the advantages that digital power brings to certain applications, secondary benefits are evident, especially at the component level. For example, supply chain costs can be lower because a single part can now be programmed to do multiple tasks. Vendors commonly put inefficient power supplies in high-volume x86-class servers because they don’t see a cost advantage in putting in more efficient components that add a few dollars to their server costs. These power supplies have a typical efficiency of 65%. Customers want up to 80% efficiency, according to Hewlett-Packard, and this could be a good opportunity for digital control.
Five"Levels" of Digital Power Management and Control
· PowerConversion–Digitalcontrol that “closes the loop” in the power converter; e.g.output regulation.
· Converter Management–Digital control inside the power converter but outside the“loop”; e.g. monitoring and status.
· Board Management–Digital power control and management of the power converter
· at theboard level; e.g. thermals, sequencing, controlling multiple converters,etc.
· Rack Management–Digital power management of thesystem; e.g. rack-level.
· Facility Management–Digital power management at the facility level; e.g. theinteraction of a rectifier front end; uninterruptible power supply and batterymanagement;thermal controls for the room;automatic transfer switch; etc.
Top 10 New Digital Power Products
1. Primarion - Launches Di-POL Family of Digital Power ICs
2. Power-One - Debuts ZM7300 Digital Power Managers
3. Microchip Technology - Offers 16-bit dsPIC30F Digital Signal Controllers
4. Linear Technology - Offers Digital Power Management Solution
5. Digital System - Monitors and Controls Telecom Power
6. ROAL Electronics - Debuts RHPS224 Series Power Supplies
7. National Semiconductor - Intros Power Management IC With Digital Control for Portable Systems
8. Intersil - Intros ISL6592/ISL6595 Digital Multiphase Controllers
9. 1U Power Supply - From C&D Delivers 1,200W at 12Vdc
10. Actel - Ships Mixed-Signal FPGA for Power Management
Click here for Illustrations:
Figure 1
