Electronic Design

ZigBee Alliance Releases the Battery-Free, Energy-Harvesting Green Power Standard

Thu, 02 Jul 2009 05:50:00 GMT

ZigBee Green Power, introduced by the ZigBee Alliance, is an energy-harvesting, battery-free feature set designed to create a global, standard technology for self-powered devices. Without needing wires or batteries, according to the Alliance, these new devices are compatible with ZigBee and ZigBee PRO networks and can enable maintenance-free, environmentally friendly products.

Triple-Current-Modulation Delta VBE Thermometry Cancels Ohmic Error Sources

Fri, 03 Jul 2009 05:50:00 GMT

Delta VBE-based (VBE) thermometry1,2,3,4 is based on this classic bipolar junction I/V/T relationship: For an ideal transistor, the VBE corresponding to ratiometric change in collector current (I2 / I1) is exactly proportional to absolute temperature: VBE = 198.4 ∝V * °K * LOG10(I2 / I1). Because cheap, common, and robust small-signal transistors conform closely to the ideal model, circuits that exploit the “PTAT (Proportional...

50-MHz Op Amps Self-Calibrate Offset

Thu, 02 Jul 2009 05:50:00 GMT

The MCP65X 50-MHz rail-to-rail operational amplifiers from Microchip Technology include an on-chip “mCal” calibration circuit that calibrates offset voltage at powerup or on-command. An internal power on-reset detector or a signal on an external pin initiates calibration. Self-calibration provides a lower initial voltage offset than conventional op amps, along with a means to continually control drift over time and temperature, Microchip says (...

My E-mail Ate My Homework

Wed, 01 Jul 2009 05:50:00 GMT

I’m becoming more forgetful these days— or rather my e-mail is (Fig. 1). Like many of you, I work for a company that limits the lifetime of e-mail. At first, this seems reasonable. It saves space, even though hard-disk prices per terabyte are falling faster than a fully populated NAS box. It’s also a great way to eliminate evidence. This policy has some unintended consequences, though, for...

ADV: New! Data logging Made Easy with NI LabVIEW SignalExpress and CompactDAQ

Fri, 03 Jul 2009 05:50:00 GMT

The out of the box, non-programming data logging solution of NI CompactDAQ and LabVIEW SignalExpress reduces your time to first measurement to seconds. Combine the flexibility of over 30 plug-in modules leveraging USB plug-and-play technology with analysis routines and HTML report generation to quickly log, analyze, and present your data without any programming.

Match Multicore With Multiprogramming

Tue, 30 Jun 2009 05:50:00 GMT

Across the embedded landscape, the design credo has become “more cores.” However, challenges remain when it comes to the software side. Some hardware architectures can deliver dozens of cores, while others hit thousands of cores. Unfortunately, applications don’t always port easily across different architectures. For the low end of the embedded space, single-core solutions will remain. It’s still possible to move up the power and performance curve by moving to...

Bob's Mailbox

Mon, 29 Jun 2009 05:50:00 GMT

HI BOB, I read your response to Arthur Williams in the April 23 column (“Bob’s Mailbox”). The answer as to whether or not to remove the ground plane underneath inductors is: it depends. If the inductors are cans or toroids, it does not matter as the fields are contained inside the inductor. If the inductors are air wound or chip inductors, it might be best to try...