http://www.low-powerdesign.com/ The engineer's portal for clean/green design Technology Tech News en Copyright 2011 john@low-powerdesign.com (John Donovan) john@low-powerdesign.com http://www.low-powerdesign.com/favicon.icohttp://www.low-powerdesign.com/ Mon, 02 Jan 2012 13:51:37 GMT Mon, 02 Jan 2012 13:51:37 GMT RSS DreamFeeder v 2.5.2 LTE-Advanced is being specified initially as part of Release 10 of the 3GPP specifications, with a functional freeze targeted for March 2011. The LTE specifications will continue to be developed in subsequent 3GPP releases. ]]> http://feedproxy.google.com/~r/Low-powerDesign/~3/Otdfo6kOKqY/article_intro_lte-advanced_part1.html Contributed by Agilent Technologies, Inc. http://www.low-powerdesign.com/article_intro_lte-advanced_part1.html.1325512293222.1 http://www.low-powerdesign.com/article_intro_lte-advanced_part1.html Three-phase motors driven by pulse width modulation (PWM) techniques are used in many consumer appliances from air conditioners and garbage disposals to adjustable beds and pool pumps. These applications typically use brushless DC (BLDC) motors with power ratings between 0.25 HP (186 W) to 3 HP (2,238 W). Figure 1 shows an example motor circuit in which the AC line voltage is converted to a DC voltage by a rectifier and then applied to the input of an inverter. The inverter then converts its DC input voltage into three AC phases that sequence power switches G1 - G6 on and off, electronically commutating the motor. The controller regulates speed by comparing measured speed to the speed set point and adjusting the switch timing until the two parameters are equal. ]]> http://feedproxy.google.com/~r/Low-powerDesign/~3/uDGO0QEXxEs/article_Alfano_121311.htm By Don Alfano, Director of Power Products, Silicon Labs http://www.low-powerdesign.com/article_Alfano_121311.htm.1323969222285.1 http://www.low-powerdesign.com/article_Alfano_121311.htm The most common types of RF front-ends for software radios are dual conversion, single conversion, and tuned radio frequency receivers. The suitability of a particular receiver topology depends on a number of parameters that may include the following: ]]> http://feedproxy.google.com/~r/Low-powerDesign/~3/vrP7mU0VCLg/article_SDR_11232011.html By Jeffrey H. Reed, Virginia Tech http://www.low-powerdesign.com/article_SDR_11232011.html.1322071569571.1 http://www.low-powerdesign.com/article_SDR_11232011.html In historical terms, the death of the flint tool, cooking by dung and other bygone technologies occurred very rapidly. This was because several factors conspired to bring in the better alternative and this created a multiplier effect. So it is with lead acid batteries. ]]> http://feedproxy.google.com/~r/Low-powerDesign/~3/usUz2QHJo58/article_death-of-lead-acid-batteries.html By Dr Peter Harrop, Chairman, IDTechEx http://www.low-powerdesign.com/article_death-of-lead-acid-batteries.html.1321634975641.1 http://www.low-powerdesign.com/article_death-of-lead-acid-batteries.html Wireless power systems are emerging as a practical option for conveniently recharging mobile phones and other handheld devices. Implementing an industry standard interface allows a common charging pad (TX) to recharge multiple types of battery-operated devices (RX). The WPC developed the Qi standard for wireless power systems with up to 5W of output power. This allows complete interoperability between transmitters and receivers independent of device manufacturer. ]]> http://feedproxy.google.com/~r/Low-powerDesign/~3/kXREhG_S7cY/article_TI-Qi.html By Upal Sengupta and Bill Johns, Texas Instruments http://www.low-powerdesign.com/article_TI-Qi.html.1320789231298.1 http://www.low-powerdesign.com/article_TI-Qi.html The motivation for the article is to present methods of enhancing a wireless link in a typical environment of simple low-power wireless transceivers. This article focuses on maximizing the reliability of a wireless link, while keeping the overall hardware costs down. For many simple transceivers the added overhead of using frequency-hopping diversity hardly seems worth while, however, this article presents strong technical reasons why this should be considered even for simple applications. ]]> http://feedproxy.google.com/~r/Low-powerDesign/~3/hJBdqE4komM/article_almholt_103011.html By Thomas Almholt, WW End Equipment Applications Marketing, Texas Instruments http://www.low-powerdesign.com/article_almholt_103011.html.1320004036825.1 http://www.low-powerdesign.com/article_almholt_103011.html Normally you order an evaluation kit to check out whether a particular microcontroller seems appropriate for a design you have in mind; if everything seems OK, you then order a more costly development kit to prototype your design. Cypress’ CY3267 PowerPSoC Lighting Evaluation Kit manages to cross that line, enabling a quick out-of-the-box evaluation within a few minutes but including a full suite of tools, circuits, and programmable components to enable developing some sophisticated lighting control systems. CY3267 PowerPSoC Lighting Evaluation Kit manages to cross that line, enabling a quick out-of-the-box evaluation within a few minutes but including a full suite of tools, circuits, and programmable components to enable developing some sophisticated lighting control systems.]]> http://feedproxy.google.com/~r/Low-powerDesign/~3/YRy10vSs_-k/article_CY3267_102711.htm By John Donovan, Low-Power Design http://www.low-powerdesign.com/article_CY3267_102711.htm.1319751882312.1 http://www.low-powerdesign.com/article_CY3267_102711.htm Part one of this two-part series covered the challenges of measuring current when developing power management schemes for battery-powered devices. To review, with battery life being a critical specification on portable devices, sophisticated power management schemes are being employed. In order to optimize power consumption and maximize battery life, engineers typically utilize advanced power-management schemes that rapidly turn on/off sub-circuits as necessary, creating dynamic current consumption typically from uA to A. ]]> http://feedproxy.google.com/~r/Low-powerDesign/~3/jUBH8VPUl-w/article_agilent_part2.html By Bob Zollo, Agilent Technologies, Inc. http://www.low-powerdesign.com/article_agilent_part2.html.1319208147493.1 http://www.low-powerdesign.com/article_agilent_part2.html The IEEE 802.11n standard was proposed through a ‘High Throughput Study Group’ effort at the IEEE. Although the major focus of the standard has been on deriving high user throughputs in a WLAN environment using multi-stream MIMO techniques, the standard’s benefits are not limited to devices with multiple antennas. There are a plethora of devices that require ultra-low power connectivity. Computers, electronic devices and machines all talk to each other exchanging volumes of information in a variety of scenarios. More than just communicate with each other, these devices form a vast, IP-based network – ‘the Internet of Things.’ In this article, we look at how these low power battery operated devices can benefit from 11n and why new designs will use 11n rather than 11g. ]]> http://feedproxy.google.com/~r/Low-powerDesign/~3/ui1pEQmrrUA/article_redpine_100711.htm By N. Venkatesh, Redpine Signals http://www.low-powerdesign.com/article_redpine_100711.htm.1318352455779.1 http://www.low-powerdesign.com/article_redpine_100711.htm Battery powered devices are everywhere, from the nearly ubiquitous cell phone, to personal electronics like MP3 players and digital cameras, to medical equipment, to industrial tools and to a vast array of military electronics. For all of these devices, battery runtime is a key requirement. An enormous amount of engineering goes into developing power management schemes to optimize runtime. Battery powered devices are everywhere, from the nearly ubiquitous cell phone, to personal electronics like MP3 players and digital cameras, to medical equipment, to industrial tools and to a vast array of military electronics. For all of these devices, battery runtime is a key requirement. An enormous amount of engineering goes into developing power management schemes to optimize runtime. By Bob Zollo, Agilent Technologies, Inc. unlinked.1318349287433.1 Portable applications need the support of battery management systems to ensure that the productivity of batteries is maintained and to deliver the best power profile over the batteries’ lifetime. In most applications today, batteries need to be replaced often and a system that can offer a means to have efficiently managed so as to prolong its life can offer several benefits. In addition to a lower overall cost since the consumer will not have to continually purchase new batteries, prolonging battery life means fewer battery replacements, which in turn means less waste. Portable applications need the support of battery management systems to ensure that the productivity of batteries is maintained and to deliver the best power profile over the batteries’ lifetime. In most applications today, batteries need to be replaced often and a system that can offer a means to have efficiently managed so as to prolong its life can offer several benefits. In addition to a lower overall cost since the consumer will not have to continually purchase new batteries, prolonging battery life means fewer battery replacements, which in turn means less waste. By Ravi Pragasam, Senior Manager, Fusion Product Marketing, Actel Corporation unlinked.1318349249273.1 Today a smart phone can hardly be called ‘smart’ if it doesn’t include a MEMS accelerometer, gyroscope and possibly a compass, too. A small niche product five years ago, MEMS sensors now constitute a multi-billion dollar industry. So what exactly are MEMS motion sensors and how do they work? Today a smart phone can hardly be called ‘smart’ if it doesn’t include a MEMS accelerometer, gyroscope and possibly a compass, too. A small niche product five years ago, MEMS sensors now constitute a multi-billion dollar industry. So what exactly are MEMS motion sensors and how do they work? By John Donovan, Low-Power Design unlinked.1301178709442.1 The typical operating voltage required for any microcontroller is at least 3.3 Volts. However, for the core in any microcontroller to be functional 1.8 Volts is sufficient. Since an AA or AAA battery will give 1.3-1.5V when fully charged, systems need at least two battery cells to operate. As the battery decay gradually falls below 0.9V, it becomes impossible to operate the system even with two batteries. The typical operating voltage required for any microcontroller is at least 3.3 Volts. However, for the core in any microcontroller to be functional 1.8 Volts is sufficient. Since an AA or AAA battery will give 1.3-1.5V when fully charged, systems need at least two battery cells to operate. As the battery decay gradually falls below 0.9V, it becomes impossible to operate the system even with two batteries. By Udayan Umapathi, Cypress Semiconductor unlinked.1301143902459.1