Unfortunately, the power requirements of today's designs are common across all companies, regardless of size, and include power management; sequencing and ramp rates, monitoring, and margining; fault detection and response; greater densities in board design; thermal management; lower voltages and tighter tolerances; higher currents; shorter design cycles.
And while the same FPGAs, DSPs, and ASSPs are being used by all companies, the available technical resources to solve those requirements are geared towards only a small portion of the market. In order for digital power to move along the technology adoption lifecycle and into the industrial arena, digital power companies must focus on 'ease of use.'
Digital power providers are already trying to focus on the concept of ease of use. They provide numerous documents to assist with component selection, board layout, and in depth compensation guidelines. These are in addition to numerous tools that support the design effort. And others offer a 4-day digital power design course to educate the end user.
But, products must be usable with minimal support for widespread adoption to occur. Engineers rarely have the time to attend 4-day classes or to scour through pages of documents looking for an answer. If the answer is not there, they need to get support from the vendor to solve the problem--a plug an play solution is needed.
Making digital power easier to use
Today's digital power solutions do not lack available features. It is the ease of implementing those features and prioritizing their use that has caused the biggest challenge for end users. Indeed, on the surface, it appears that the industry has been leaning more towards solving the 'would like to have' rather than focusing on what is truly needed.
With the shift to digital, software tools have become a part of the design process, and the ease of using these tools must be taken into consideration. The FPGA and microcontroller companies learned long ago that design tools can win or lose designs regardless of the feature set within the silicon solution. If it takes too much time to implement the features, the reward to the customer is not worth the effort.
Power is the necessary evil
When speaking with engineers and managers at companies outside of the largest OEMs, a common theme continues to surface: 'power is a necessary evil.' Engineers are valued on the IP they create for their company, not necessarily for the power supply design. The reduction in engineering staff has forced engineers to not only create company IP, but to then figure out how to power the design. Because of this and the continuously shortening design cycles, the power architecture is one of the last items to be addressed.
Unfortunately, time to market is even more crucial for smaller organizations--such as Europe's vast array of medium sized industrial firms--as this can make or break a product and even potentially a company. Today's design engineers need a solution that can be truly "cut and paste" to solve the continually shifting demands of power.
Figure 2: Distributed Power Architecture
Figure 3: Smart Grid Platforms
Power firms are beginning to address these needs and the fundamental philosophy behind these new classes of product is, what we at CUI dub, "Simple Digital"; a way to control the platform based on an intuitive, easy to use design tool to greatly simplify what was once the time consuming 'black art' of designing analog compensation loops.
In analog, these control loops were suboptimal by necessity and designed for worst-case conditions. The automatic compensation feature gives an engineer the ability to layout the circuit and then let the module perform its own compensation calculations, adjusting in real-time. It essentially eliminates the 20+ page compensation application notes and tools from other vendors and incorporates the compensation into the IC directly. In addition, auto compensationwill continue to compensate the circuit throughout the life of the product on a cycle-by-cycle basis so the circuit is always in an optimal state. This feature dramatically reduces the design cycle and increases the reliability of the circuit when compared to an analog solution.
Using our Novum digital power supply technology as an example, new digital power modules are coming to market that are targeted directly at engineers who want to solve today's issues in a simple plug and play manner. The product family contains devices with industry leading efficiency and functionalities – such as the NDM2Z and NDM2P series – and from these we worked backwards to create devices – such as the NSM2P--that use a No-Bus platform to deliver this functionality in a format analog design engineers will be used to working with, making it easier to make the switch. Each series has a unique set of features to address today's power design requirements.
Joining the "haves"
The switch from analog to digital power supplies brings significant benefits to a system in terms of efficiency and optimization through real-time monitoring. The development of new classes of power supplies that are more intuitive and designed to meet the needs of engineers at small and mid-sized industrial OEMs will enable a far more diverse range of organizations to access its advantages.
(Click on image to enlarge)
Figure 4: Transient Response 25 A Module
Mark Adams is senior vice president at CUI and has been with CUI since 2009. Adams has over 20 years of industry experience and is an expert in digital power; leading the company's shift into advanced power products. He studied at Central Washington University and received his commission from Army ROTC, serving in the Army National Guard for 13 years.