Caption for this is: Ericsson raises the bar with high-current 780W power interface module for ATCA applications

December 21, 2016 // By EDN Europe
By Martin Hägerdal, Head of Ericsson Power Modules
The story of digital power in 2016 could be viewed simply as ‘more of the same’: server power demand continues to rise, while operators become increasingly concerned about the cost of wasted energy. Innovative products and techniques that can significantly boost power-supply efficiency are emerging. In the AMP Group, the power industry appears to have found an effective way to minimise the cost and supply risks that system architects and end users have traditionally had to accept in exchange for using advanced, but proprietary, power converters.

Rising Power Trend Continues

High-performance servers used for telecoms and cloud computing are driving innovation in power modules. The market for cloud infrastructure services continues to grow strongly, and exceeded $7 billion per quarter in 2016, according to analysis by Synergy Research, reported in Datamation .  

As demand for cloud services grows, leading providers such as Amazon, Google and Microsoft are investing massively in technology, setting up new data centres and boosting the capabilities of existing facilities. These demands are setting the pace of development, and in power terms, the trend continues to be upwards. Some of the most power-hungry applications Ericsson Power Modules has been asked to work on this year have been as high as 3kW.

On the other side of the power equation, integrated circuit (IC) core voltages have ducked below 1V, driven by improvements to the process technologies at the heart of modern server processors, application-specific integrated circuits (ASICs) and field-programmable gate arrays (FPGAs). These falling supply voltages are driving up current consumption: some of today’s chips can peak at over 100A. Power modules, such as Point-of-Load (POL) converters, must be able to supply this demand. It has never been more important for power module manufacturers to pay close attention to the advances chip makers are achieving.

The pursuit of energy efficiency and compute performance continues to dominate the demands of equipment buyers. This is drawing interest in direct power conversion from a high bus voltage, such as 48V, to POL voltages such as 1V or lower. Some proprietary modules, suitable for direct conversion, are already available, although a more open, industry-standardised approach could deliver advantages through the greater security of supply and the lower cost of ownership that come with vendor-independence. Direct conversion is not completely new: it was often used in distributed power architectures in the late 1990s, although intermediate bus architectures have subsequently become more popular. Inserting the intermediate converter enabled system builders to use smaller, lower-cost, non-isolated POL converters to save on the cost of the expensive, isolated quarter-brick modules traditionally used to generate IC supply rails from the DC bus voltage. 

While energy efficiency has taken over as the chief concern of power-system architects, they also want to free up board space for more and larger processors to handle increasingly intense computational loads. This brings with it the potential for hybrid systems, which combine intermediate bus and direct conversion modules, to raise the efficiency of high-current converters by several percentage points, as well as using smaller intermediate bus conversion (IBC) and direct conversion modules to save space. In 2017, Ericsson plans to deliver digital power modules for direct conversion which will present an attractive economic proposition to power-system architects and end users.

Looking back at 2016, Ericsson introduced two significant new modules. The 780W PIM4710PD Power Interface Module can deliver up to 20A of output current in a quarter brick size, and targets Advanced Telecom Computing Architecture (ATCA) server applications. This module alone can handle up to 1080W with a 54V input, industry-leading performance. In June, Ericsson introduced the BMR458 advanced bus