“Intersil’s history in power is long and deep,” says Mark Downing, Senior Vice President of Corporate Strategy at Intersil (pictured above). “In the mid ‘90s, we provided Intel’s VRM multiphase solutions for high current loads for processors and over the years the company has refined its IP and performance in that space serving everything from desktops and notebooks and now for servers.”
This multiphase technology has proven key for areas as diverse as automotive power and data centre systems and the results of previous investments are starting to emerge.
“Three years ago we looked at the businesses and saw the key was in power management, so the decision was to focus around that (apart from automotive and radiation hard, but even in those markets we have a strong focus) so we doubled down on power and we are just now starting to reap the benefits of that decision,” he said.
“We’d seen this continual trend in power towards higher power density and if you put it in context of the load, whether a processor, an ASIC, FPGA or embedded SoC, what you are seeing is many more voltage rails. This puts a premium on being able to power those chips in the smallest possible space. That’s one trend that we saw and based on that we increased our investment in power modules because we saw a need for power density and ease of use. These days customers don’t have time to design power systems and in many cases don’t have the expertise and they are under pressure to deliver a solution quickly.”
This creates a competitive tension with the open frame power supply makers as the semiconductor companies take on more of the module market using IC packaging techniques.
“Companies like Intersil and our competitors have taken on the task of taking the controller, driver, FET, inductor and some of the passives and integrating those into an IC package, so we call it a module but it’s in an IC package that has the same ease of use as an open frame module but in a smaller footprint. In some cases we supply controllers and integrated FET switching modules to vendors but they tend to focus on higher power,” said Downing.
“We are pushing higher currents up to 80A and we are looking at how to take that beyond 100A so we are infringing on their space going forward, but we tend to coexist in many customer applications – a 48V IBC [intermediate bus converter] for example will still be using an open frame module,” he said. “For a given current level we have a better thermal performance in the packaging but there are limits and we continue to look at ways to expand that. It also depends on innovation in the packaging so we work closely with subcontractors to drive that innovation.”
“Another trend we saw was digital power, and we acquired Zilker Labs in 2008 because we saw the trend back then,” said Downing. “We realised three years ago that we had not invested enough in digital power which was coming of age but we are seeing early indications of that emerging in the hyperscale data centres who are now adopting the technology,” he said.
The other strand to Intersil’s power strategy is automotive.
“In the automotive space one of the real changes is how to provide functional safety and performance at the same time so we decided to invest more in that area,” said Philip Chesley, Senior Vice President for Precision Products. “We had a good footprint through video decoders in automotive designs and we had a small but growing power position around that footprint so we expanded that. We are still doing that [those decoder designs] but we are really focussed in two areas – the first is cell balancing for full electric vehicle (EV) designs, basically anything that’s using a lithium ion battery.”
“The other area we are investing in is the emerging 48V system to meet emission standards – what’s driving the transition is the fines that are going to be imposed on car makers. The 48V system fits between a start-stop system and a full hybrid and that allows them to meet the emission goals. The issues with VW have made things go faster,” he said.
Here the technical challenge is to handle between 1 and 3kW bidirectionally, which requires the multiphase capability that is core IP at Intersil. “There’s enough momentum in Europe and Asia for the initial stage where you will use a 48V system to recapture more power than you can with today’s 12V alternators to give smoother operation, and that’s definitely going to happen. It takes longer than everyone thinks, but that will continue,” he said.
Battery management is going to grow fast and for Chesley, the charge time is equally important as range. If you can charge the batteries quickly then range is less of an issue, he says. “That’s all power management problems as well as battery chemistry,” he said. “We are somewhat agnostic as to the battery chemistry – it does drive the accuracy of the cell balancing and the voltages but for the fundamental current sharing and ensuring accuracy, that architecture is agnostic to the chemistry.”
Data centre innovation
The figures of merit of a power supply continue to increase, with a data centre multiphase supply is peaking at 96% and full load at 93%. A 1% improvement in efficiency is a 15% saving in power costs, but its more about improving efficiency across the power curve, says Downing. “Across all sectors you are seeing a widening of current levels for both peak and light loads – in mobile devices you have quiescent currents in the low microamps and peak currents pushing 15A today and 20A in the future with the next generation 7nm chips. The same is true in the data centre, they spend a lot of time in idle mode and maintaining high efficiency at low current levels is critical.”
“Some of the data centre customers are actively talking to us about how to go beyond improving the efficiency of the power to the processor and talking about how to intelligently scale power across servers and the data centre and that requires new power management schemes and new interfaces, and some of the technology just isn’t there today,” he said. “It’s about how you get the communication across all these different processors, multiple servers and expand that so you are matching the power delivery to the needs of the data centre.”
However the chances of standardising this is low, he says.
“In the data centre world I don’t know if a standard is possible. Google has been innovating in 48V in data centres for point of load architectures and they recently donated that to the OpenCompute platform, but you wonder if they are already working on the next thing.
“We have been supplying public cloud data centres providers for the last three or four years, and we see the challenge of balancing standards with innovation. I tend to feel they favour the innovation and differentiation more than the standardization. It does inhibit innovation. For example, you can take the common footprint such as the 6×6 HPmos module but we developed a 5×6 which is smaller and you save board area. You can end up in standardisation in a sub-optimal performance – there are always tradeoffs and you have to weigh those up.”
The Internet of Things is also driving new power management requirements for energy harvesting and ultra-low-power operation.
“There are some real opportunities there for innovation and it’s something we are focussed on,” said Downing. “Our thoughts are on providing highly integrated PMIC type products that are optimised for very low power operation working with a small coin cell source or potentially an energy harvesting solution. That’s the initial focus. We have to be a little selective as the IoT is a little ethereal as to where the real applications will come from, so we are being thoughtful about where to target the initial markets. One of the higher volume markets is in the wearable market and the same IP we are developing there could be applied to sensor nodes but we would probably be doing that with the guys integrating the MCUs and RF.”
“For now we think the requirements are such that it’s not readily integrated. Ultimately, it likely will be, so partnering with those companies initially is the right engagement model,” he said. “We could license the technology for high volumes but many of the industrial markets don’t have those volumes and need more variants so the more diverse industrial IoT still represents a standalone product opportunity.”
“We have seen an acceleration in consolidation and it’s an interesting dynamic,” said Downing. “Customers are looking for a high level of support and more of a system level solution so on the one hand consolidation can assist that with a larger portfolio, but I don’t think that precludes small or mid-sized companies being able to compete by focussing on a system level solution in a targeted space.”
“For markets such as automotive that need multiple sources that is a concern, but that has opened up opportunities for us. In the last 18 months to 2 years customers are actively looking at the supply base and trying to guess what will happen so that it doesn’t impact the business.”
Other Power Trends interviews:
All change at Stadium power
Small is beautiful – Exar
IoT drives the move to software defined power – CUI
Microsemi sees integration from device to module drive innovation