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Imec Boosts Bluetooth Battery Life

Low-voltage circuit extends battery life by 50 percent

2 min read
Close-up of a Imac chip
Photo Imec

A Bluetooth transceiver design that dramatically boosts battery life could enable richer sensor networks and extend the lifetime of implanted medical devices. At the International Solid-State Circuits Conference in San Francisco this week, engineers from European research organization imec and Renesas Electronics Corporation (a semiconductor company in Tokyo) showed off the record-low-voltage communications chip.

Over the past eight years, engineers have brought down Bluetooth power consumption by a factor of ten, says Christian Bachmann, program manager for ultralow power wireless systems at imec Holst Centre in Eindhoven, Netherlands. The imec transceiver, which meets the Bluetooth 5 standard, uses 0.8 volts, down from a full volt. That reduction is enough to extend battery life by 50 percent. “This achieves another power of five reduction and will enable new applications,” Bachmann says.

One way the imec-Renesas group managed to trim power requirements was by switching out analog circuits for digital ones. Bachmann says the last few years have seen a lot of innovation in digital radio designs, and the imec group took full advantage. Digital logic is not only more reliable and compact than analog counterparts, it’s miserly in its use of power. One significant switch to digital in the Bluetooth transceiver was in a control circuit called a phase-locked loop. The digital version offers better control, says Bachmann. The team also made architectural changes, including ditching an entire block of analog-to-digital converters in the receiver. Typical systems require two sets in order to ensure quality of the signal; the imec-Renesas converter works with high enough fidelity that only one is needed.

Bachmann is excited about the potential for ultralow-power communications not only to extend battery life in conventional applications, but also to open up new ones. “For wireless sensor networks, communications are the power bottleneck,” says Bachmann. Power-hungry transceivers can rule out the use of low-voltage printed batteries and energy harvesters. More efficient transceivers could open up new possibilities for wearable electronics and distributed sensor networks.

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Why Functional Programming Should Be the Future of Software Development

It’s hard to learn, but your code will produce fewer nasty surprises

11 min read
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A plate of spaghetti made from code
Shira Inbar
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You’d expectthe longest and most costly phase in the lifecycle of a software product to be the initial development of the system, when all those great features are first imagined and then created. In fact, the hardest part comes later, during the maintenance phase. That’s when programmers pay the price for the shortcuts they took during development.

So why did they take shortcuts? Maybe they didn’t realize that they were cutting any corners. Only when their code was deployed and exercised by a lot of users did its hidden flaws come to light. And maybe the developers were rushed. Time-to-market pressures would almost guarantee that their software will contain more bugs than it would otherwise.

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