Digital power parallels the FPGA market

To figure out where the digital market is going, look to the history of the FPGA market

BY MARK ADAMS
CUI, Tualatin, OR
http://www.cui.com

Many articles have been written on the advantages of digital vs. analog power solutions. The argument is indeed compelling, but while many previous topics have centered on the performance advantages of digital power vs. analog, this article seeks to discuss the business economics that will drive the implementation of digital power solutions now and in the coming years. If one wants to peer into the future and understand where the digital power market is headed, they should look no further than the FPGA market and the evolution that has occurred over the past decade.

Many of the benefits that digital power and FPGAs offer are not measured in component costs and percentage points of efficiency, but instead in increased revenues and reduced development timeframes and cost. The factors that have prompted many companies to make the move to FPGAs from ASICs are the same factors that will prompt companies to make the move to digital power. The FPGA market is quickly growing to a $5-billion industry, but it didn’t really begin to take off until the late 1990s. Until the boom at the end of the 1990s, design cycles of 2 to 5 years were considered the norm, based mainly on ASIC platforms. These ASICs would require multiple design spins to achieve an acceptable level of performance, but on a component cost level, they were much cheaper than FPGAs. Up until that point, companies could not justify paying up to $1,000 for an FPGA when they could get equal and often better performance from an ASIC at fractions of the cost. ASIC cost and performance capabilities were the most important factors driving design decisions.

During the economic boom of the late 1990s, this all changed. Time to market and flexibility in design cycle became more critical as competitive pressures increased. The industry quickly became a “now” market. If companies didn’t have a product to release in a short timeframe, the window of business opportunity would close (see Fig. 1 ). Companies thus started valuing time to market over actual component cost as they realized that earlier time to market meant quicker revenues and a greater market share. An added advantage of being an early market entrant was that companies were able to build a brand presence, ultimately increasing their longevity within the market. This mindset drove the electronics industry as a whole to make a paradigm shift. Companies understood that if they were to prosper, they needed to be nimble, reacting as quickly as possible to changing standards, customer needs, and last minute product definitions. The ASICs that historically had been the backbone of many designs no longer fit this model and companies started to migrate towards FPGAs to implement in new designs.

Fig. 1. Time to market and flexibility in design cycle became more critical as competitive pressures increased.

FPGAs offer a dynamic solution that reduces development cycles, allows for easy IP reuse, and eliminates the need for many secondary chips as the functions can be implemented in the fabric of the FPGA. These attributes are the primary reason that today the market is dominated by FPGA starts over ASIC starts. According to Gartner Research, the ASIC market in 2009 had 4,000 starts compared to the over 11,000 starts in 1997. This reduction is in stark contrast to 120,000 estimated FPGA starts seen at the end of this same timeframe. ASICs have been relegated to only the highest-volume applications.

The same business value propositions that FPGAs provide can be found in digital power products.

Fixed versus dynamic

An analog power solution, like an ASIC, is a fixed solution. This means that changes on a particular power rail, such as voltages, sequences, or ramp rates, require the design to also change. Components will need to be removed and exchanged for other values, often necessitating a completely new layout to accomplish the desired requirement. This delay could cause a company to miss a market window with their product, or at a minimum, enter the market late. A digital power solution, on the other hand, allows the customer to make changes dynamically to an output voltage, timing, sequencing, and numerous other power management functions. This is one of the significant advantages in using a digital power solution. Digital provides the flexibility to optimize design performance and alter designs without halting the design process or incurring expensive board re-spin charges.

A digital solution also offers incredible flexibility when designing-in today’s cutting-edge technologies. Companies often rely on the newest ASIC to implement one or more functions in their product. Design decisions are often made based on a preliminary datasheet from the IC vendor. Layout may even start based on this preliminary datasheet. When the final datasheet and first samples arrive, however, the power structure outlined in the preliminary datasheet may have changed. With an analog solution, it is difficult to make these changes without a re-spin or an evaluation of the new solution with a non-optimized analog power design. A digital solution can easily handle the changes, allowing for a quick evaluation of an optimized solution.

Development

In addition to flexibility of design, the value of digital is seen throughout the design cycle. During initial board power on, boards are often powered up and then immediately go back down. The engineering work then starts in trying to understand the cause of the issue. With an analog solution, the engineer must rely on trial and error by probing the design and components to find the root cause. In contrast, digital power gives the engineer the ability to know exactly what went wrong — in real time. Digital power solutions not only monitor the power rails, but they also manage faults within the rail. On a digitally controlled board, the engineer powers on the board, and when it goes down, he can immediately go to a graphical user interface (GUI) provided by the vendor to look at what caused the error. The GUI highlights the fault and the engineer then makes the necessary change, often done in the GUI, and a power on is once again attempted. This process takes a fraction of the time typically seen in a traditional analog trial-and-error method.

Design reuse

In today’s competitive business climate, once one design is completed, the next generation on the product road map is usually already underway. When a designer attempts to use a previous analog solution in the new design, the fixed circuit based on the previous board specifications usually cannot be implemented “as is.” The new design will have different timing needs, sequencing, and faults, all requiring the designer to implement a new layout to incorporate the modified requirements. The core components may be reused, but the analog solution itself must be modified. Digital designs, due to the dynamic nature of the solution, can be easily “cut and pasted” from one board to the next. Any required changes can quickly be implemented through the GUI.

Data analysis in verification

Analog systems by definition are “dumb,” giving the user no information in order to do a proper analysis of the power consumption of the system. Digital, on the other hand, can monitor and report on output voltage, input voltage, current, and temperature. With this valuable information, a company can run their system in real world scenarios and measure all of these data points in real time. For many companies, the ability to gather this data under numerous conditions will dramatically reduce the design verification process.

Digital modules

CUI developed an easy-to-implement point-of-load (POL) module that incorporates all of these digital power attributes into a compact module design (see Fig. 2 ). Novum simple digital modules are the latest addition to the V-Infinity power line. They are focused on providing complete, easy-to-use solutions to make digital power accessible to a wide array of users. The module designs are cost effective and simple to implement, using standard PMBus commands for configuring and monitoring. Integration of Powervation’s patented Auto-control technology also allows the new modules to work in real time, ensuring stability and improved transient responsiveness.

Fig. 2. Easy-to-implement point-of-load modules incorporates digital power attributes

The Novum modules come in a compact footprint, have programmable outputs, and offer a wide array of digital control functions. The product is currently offered in two configurations, 12 and 25 A, depending on your power needs. ■