Posted on 05 February 2020

Bringing Value Back to the Power Equation




Over the past decade, the power industry has continually been driven by demands for cheaper power supplies. The notion that “power is a necessary evil” is still the underlying sentiment, even in a world that demands greater performance and efficiency from its devices.

By Mark Adams, CUI

And, while it’s true that power is not what makes the internet work; it is the sophisticated processing infrastructure of switches, routers, servers, etc that drives the web, it is quickly being realized that the power system can no longer be an afterthought when performance and efficiency is a priority.

Times are Changing

At the start of a typical design project, the marketing requirements document is given to the engineering team and it can usually be summed up in a very simple sentence - “For this project we need 2X+ the processing power in the same PCB space and at the same bill of material cost.”

Semiconductor companies have been able to stay ahead of these market demands thanks to advances in manufacturing that have allowed for greater densities of processing power. But, that comes at the cost of needing more power for that chip. 75A+ board level power rails used to be limited to Intel and AMD processors, which (unlike the majority of their customers) both had the extensive power design teams to handle this task. Now, however, the companies utilizing these new generations of chips typically have design teams that rely on non-power centric engineers, making it harder to get the power system right.

Unfortunately, the power industry has not been able to stay on par with the rapid rise in processing performance. To complicate matters for power supply companies, while demand for faster access to larger amounts of data via a reliable and secure infrastructure accelerates, the expectation is that board mount power supplies will keep up with new levels of performance at the commoditized price levels of the past. Some of the chips used in networking equipment can cost upwards of $1000, yet the focus on the modules powering these devices is still on cost. That is akin to buying a Ferrari, but then installing the engine of a compact car to save cost. It will look nice on the outside, but won’t perform to the expectations of a Ferrari. The reality is that it is very difficult to get (for the lack of a better term) “good and cheap.”


Previous to the newest generations of semiconductors, the industry as a whole had set an expectation and a roadmap methodology that they would design better products, cheaper—and that power should be considered a commodity with multiple sources available. Now that performance requirements for a range of advanced ICs have skyrocketed, this expectation is no longer reasonable.

One of the significant drivers of pin compatible power supplies in the board mount dc-dc area has been the Distributed-power Open Standards Alliance (DOSA), as well as the Point of Load Alliance (POLA). These alliances were formed to drive power supply compatibility across numerous isolated and non-isolated form factors. POLA was the first to announce this initiative in 2003 and DOSA announced in 2004. The intent of each of these alliances was to provide the customer base with a pin compatible second source for their board mount dc-dc power supplies.

Board mount dc-dc power supplies

Each of them came about it in a different manner. POLA was a smaller group of companies and the intent was that each POLA power supply utilized the same schematic. DOSA focused on the mechanical aspects, dimensions, pin-out, and functions. At that time an alliance of power supply companies seemed logical and was a need driven by the customer. The industry had come out of an internet bust and the customer base had been burned by companies that were sole sourced and didn’t survive the downturn. They were forced to redesign many projects in order to eliminate sole sourced products that could no longer be purchased. This by no means was limited to the power segment, but nonetheless it drove the industry overall to require multisource products.

Today, DOSA continues to define standards and in 2010 added the first standard that included a digital bus. POLA on the other hand seems to have lost focus and has not released a digital bus converter or other standard release part for several years. An alliance like DOSA has value to the customer in some applications, but it does have limitations.

An alliance by nature is focused on serving the masses or the widest market segment in order for everyone to participate. However, that only covers 90% of the market…it is the other 10% that is the problem. When a power supply company designs to a specific mechanical, the opportunity to innovate becomes limited.

Today’s Need

The power architecture design process had typically looked to reuse as much as possible from the previous design. This is a logical process when the priority is to reduce development costs and streamline the AVL, but the problem is that POL power supplies have not been keeping up with the requirements of the next generation chips. The opportunity to reuse previous power designs is no longer a viable solution for many new applications.

In today’s complicated designs, the initiatives of old cannot satisfy some of the most challenging power needs. Innovation in power supply design is critical to meet requirements that are pushing 75A+ per rail. A design of this nature is not trivial, and requires companies to embrace the idea of bringing value back to the power supply. Commoditized power supplies simply cannot meet many of these expectations.

Innovation is associated with the dirtiest of four letter words, “cost”. If you spend money on innovation, it will cost more. In reality it is exactly the opposite. The value, or total cost of the solution, should actually be lower when a complete analysis is done.

A simple example of this is CUI’s Solus® Power Topology. Our first POL development based on this patented SEPIC-fed buck topology has significant advantages in transient response. This is a problem that many designs solve by laying out a dump truck worth of capacitors on the output of the POL module. This new topology will allow for a 50% reduction in expensive, bulky output capacitors, compared to competing digital POL products on the market. This is in addition to the significant increase in density and efficiency that our new topology provides. In this scenario you cannot compare module cost alone. The total cost of the solution, including the cost of required external components, board area, and complexity of design must be factored into the equation.

Innovation doesn’t always need to be limited to technology or topology. Innovation can also apply to mechanical design improvements. The mantra, “We want more in the same space” usually refers to the X & Y axis of the board. However, in many designs the Z axis of the design has room that is not being utilized. In our POL design utilizing Solus Topology, CUI has taken a unique approach and will offer the same exact module in a vertical and a horizontal orientation. This will allow the engineer the opportunity to leverage technology and packaging to find the optimal balance to achieve the requirements of their design.

A Different Approach

Not all designs need ground-breaking performance from their power modules. Simple power conversion via commodity-type power supplies can fill numerous needs. However, power supply companies need to push outside the historic path in order to satisfy the requirements of the growing number of advanced ICs introduced to the market. As systems become more sophisticated, there will be an increasing number of sockets in each design that push the limits of existing power supplies and cannot be supported with commodity modules.

Through our Novum® Advanced Power group, we’ve made it our mission to properly understand the power requirements of tomorrow’s networking designs. Engineers are looking for power supply partners that will work to provide a balanced portfolio of products able to address the more “standard” power needs as well as those that push the limits of traditional power designs. CUI was the first to release an auto-compensated POL module and the first 50A digital POL product, and is pushing to densities and performance to satisfy the new higher density/performance requirements. CUI continues to invest in innovation that will support those difficult power requirements, and we also have growing portfolio of standardized products that can support a wide range of needs. In addition, through cooperative agreements with companies like Ericsson Power Modules, CUI offers leading products and footprint alliances with companies that are also driven to meet the needs of today’s sophisticated/complex systems.

Be sure to visit our booth (1233) at the Applied Power Electronics Conference (APEC) in Fort Worth, TX from March 16-20 to learn more about our solutions to the power challenges of next-generation networking applications, including the latest high density modules based on CUI’s Solus Power Topology.


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