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Ultra-low power microcontrollers for compact wireless devices

8/1/2011 04:02 PM EDT
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Les_Slater
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re: Ultra-low power microcontrollers for compact wireless devices
Les_Slater   8/4/2011 11:06:10 AM
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Ray, I started looking at this issue in 1988 when I was a Principal Engineer at DEC. There I proposed looking at power consumption based on cumulative energy dissipated by node transitions derived from simulation traces. This was to be then added to static power. Nobody paid any attention to that proposal. Les

Ray Keefe
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re: Ultra-low power microcontrollers for compact wireless devices
Ray Keefe   8/3/2011 9:04:23 PM
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Hi Les, agreed. Iusually think of there being 4 components to ultra-low power. And a balance between them has to be obtained: - energy per instruction - instructions per task - energy per sleep interval - time to wake I consider the wake/sleep transition to be an area not usually looked at closely enough so my congratualtions to the author for bringing this up.. This is where a device like the MSP430 did so well for so long. The fast start from sleep using the DCO, quick execution at low energy per instruction, and fast return to sleep worked well in its favour. Ray Keefe Successful Endeavours www.successful.com.au

Les_Slater
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re: Ultra-low power microcontrollers for compact wireless devices
Les_Slater   8/3/2011 7:03:37 AM
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The biggest take home message I get out of this article is the extent we have to reset our brains. Common sense might tell us that minimizing active time so that we can spend most of the time sleeping is the path to lowest energy consumption. However, looking at figure 4 reveals this is not necessarily so. Time constraints permitting it would be best to run this architecture at 73 KHz to realize the approximately 25pJ per instruction. Running at the lowest energy expenditure per instruction renders the lowest total energy for a given computational task. Even if the active time involved is a substantial portion of the cycle it still uses the lowest total energy. Looking at power or current can be quite misleading. Les Slater Chicago

Jerry.Brittingham
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re: Ultra-low power microcontrollers for compact wireless devices
Jerry.Brittingham   8/2/2011 6:34:27 AM
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Where do I get a RF device that only takes micro amps?

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