The power management business is getting bigger by the day. Energy costs and environmental concerns are driving this, and neither is going to become less important any time soon. Depending on how you define power management, we estimate that it’s a market of some $15 billion for silicon devices. The market that we serve with Exar products is today worth about $1 billion, including analog and mixed signal devices – some of which have a big digital element.
One of the most important developments of recent years has been the growth in programmable power controllers, which use digital technology. Naturally, there was some reluctance on the part of analog designers to embrace digital devices but the arguments in favor of digital power management are now so compelling that they’re hard to ignore. This product area is a good fit for Exar because the company has a strong heritage in both analog and digital technologies. We’re not wedded to either one; we simply focus on developing silicon that produces the best possible functionality and efficiency for our customers, which are primarily in communications and industrial markets.
Consider designs that use FPGAs, DSPs, applications processors, media processors or microcontrollers. These usually need several voltage rails: 5V for analog, 3.3V for digital, 1.5V to 2.5V for memory and one for the processor core or cores.
To deliver these separate voltages using analog regulators takes a lot of components and a lot of board space. It adds complexity and it is very restrictive as the system design progresses.
A programmable digital power management controller cuts both component count and manufacturing costs. For example, one of our XRP77xx programmable switching controllers can form the basis of a 4-rail, flexible power control circuit using just 33 components. The chip itself is in a TQFN40 6mm x 6mm package and, depending on the exact part, the input voltage can be anywhere from 4.75V to 25V with user-configurable outputs from 0.6V to 5.5V. Similar functionality delivered from an analog circuit would need over 4X as many components, so it would be inherently less reliable – and even then would deliver inferior performance and features. But functional integration is only part of the story.
If you use analog regulators and you need to change any aspect of the power circuit you’ll need a board re-design, more component inventory and time to implement these changes. When your power management controller is programmable, in our case via a software design tool with a simple GUI, you eliminate these problems. You can very quickly adjust voltage rails, set up precision power sequencing, implement voltage and current monitoring, and program conditional fault handling.
As system development progresses, it’s very easy to adapt the power system to accommodate changes, so programmable power management can be a big help in reducing time-to-market for new products. But it goes further than that. We’ve come across instances where it’s desirable to make small changes to equipment in the field to improve its performance. Programmable power control facilitates this field serviceability. A simple firmware upgrade, delivered via an integrated I2C interface on the power controller can be used to take a supply rail up from 1.2V to 1.3V, for example, in order to improve the performance of the part of the system it feeds. A lot of designers have learned that the nominal voltage supply figure shown in a semiconductor data sheet is not always that at which it will deliver best performance in a given application.
In addition to these advantages, programmable power controllers give you the opportunity to minimize system energy consumption under all load conditions. This is important because many systems operate well below full load for much of the time. For example, a data center only gets close to operating at full load during periods of maximum data throughput. That might only happen for 10% of the time. You also need to minimize energy consumption for the other 90%. Distributed power architectures using point-of-load converters and programmable controllers give you that capability.
Power management is not just going digital, it’s going programmable. And with the right tools to simplify the programming, analog designers are now learning to love digital, rather than shying away from it.
The italian version on EONews 565-June