Thirty Years Of DC-DC Power Technology Leadership

It was in late April 1983 that Ericsson launched the world's first high-frequency switching DC-DC power modules, called the PKA family. Designed to power ‘distributed power architecture’ systems, the PKA family was five times smaller and offered 20 times higher reliability compared to competitive devices, with an MTBF of two million hours.

While the formal establishment of the Ericsson Power Modules operation was in 1981, the Power Division within Ericsson was actually started in 1977 beginning with research into high-frequency switching DC-DC converters and the establishment in Sweden of the company’s first advanced design facility for miniaturized DC-DC converters.

Innovation over Three Decades

Many award-winning introductions from Ericsson have followed the launch of the PKA family in 1983, including the PKC series introduced in 1987, which was the first high-density low-profile DC-DC power module that was only one-half the size of conventional products and offered up to three regulated outputs. This was also the age of the space-saving half-brick design, followed by the quarter brick and the eighth brick – units offering smaller and more compact possibilities in design. In the 1990s, the first miniaturized DC-DC converters became available, the PKF MacroDens family, and by the mid-1990s, the industry saw the first DC-DC converters offering more than 90 percent efficiency. And in 2001, the company was first into the market with lead-free products such as the PKD series of DC-DC converters. These products introduced new and advanced assembly technologies such as lead-frame welding.

Emergence of the Intermediate Bus Architecture Early in the decade, 2003 saw the introduction of the Ericsson PKM-C series, responding to new high-current demand in seen in distributed power architectures, still the pervasive architecture in the industry at the time. The PKM-C series used an enhanced footprint called ‘The Double-P’ to decrease power losses and improve thermal behaviour.

One of the most significant trends in the industry over the past three decades has been the gradual move from the distributed power architecture to the ‘intermediate bus architecture’. Introduced in 2000 within the telecoms and datacoms industry, the IBA board-level power architecture uses master intermediate bus converters to convert a traditional 48V(DC) distribution-level power line used in telecoms to typically a static 12V(DC). This first down-conversion 12V level feeds a number of DC-DC point-of-load regulators, which supply the final load voltages at logic supply levels of 5V and below.



Analog to Digital

The past few years have seen the beginning of the transition from analog to digital control of power converters. In 2005, a standard was born providing a method to communicate with converters over a digital communications bus: the PMBus standard was based upon the SMBus. Following this was the introduction of very high-efficiency and high-power-density IBCs, including the first fully digitally controlled and programmable quarter-brick BMR453 series in 2008; in addition to a wide range of POL regulators for use in IBA power systems, such as the BMR450 and BMR451 20/40A digitally controlled regulators.

Dynamic Bus Voltage

The latest power-system-level evolution has been the increasing use of the ‘dynamic bus voltage’ technique, which provides the possibility to dynamically adjust the power envelope to meet load conditions. It achieves this by adjusting the intermediate bus voltage via the use of advanced digital power control and optimized hardware combined with an energy-optimizer series of algorithms. This can lead to reductions in both energy consumption and power dissipation, which in turn contributes to a reduction in the amount of required cooling. The introduction in 2012 of Ericsson’s FRIDA II platform BMR456 and BMR457 have delivered advanced board-power-consumption monitoring and control technologies to power system architects enabling significant energy savings between 3 and 10 percent at board level.

History

“Ericsson has played a substantial role in a DC-DC power market that has seen considerable innovation over the past thirty years,” said Patrick Le Fèvre, Marketing and Communication Director, Ericsson Power Modules. “The company has consistently delivered leading-edge products including high-efficiency and digitally controlled advanced bus converters and point-of-load regulators to help its customers in datacoms and other industries to make significant energy savings.”