I just wanted to share a link to the Energy Harvesting Journal. This is a great place that has some very interesting articles and a collection of great technology that focuses on energy harvesting.
“Energy Harvesting Journal provides you with a free daily update of the latest industry developments. Launched in February 2009, this free portal covers progress of energy harvesting and energy storage in all its forms.”
Please take a look, it’s worth it!!!!
Supercapacitors can be used to give you the extra power burst you need to support wireless sensor nodes operating from low power energy sources or energy harvesters. A low-power energy source such as a 3V watch battery or a solar, heat or vibration-energy-harvesting module can usually supply the average power required for a wireless system, but may not be able to provide the peak power to transmit data over wireless networks such as IEEE 802.15.4 (Zigbee), 802.11 (WLAN) or GSM/GPRS.
Zigbee transmission (peak power 10 – 100mA) will shorten a 3V button battery’s life, and require a larger battery than would be necessary to support the average load power. Even worse, a 3V battery cannot support a GSM or GPRS transmission (peak power 1 – 2A) at all without some additional source of power.
The CAP-XX BritePower solution resolves these issues with a single-cell, thin-form supercapacitor that stores energy generated at low power by the battery or from the environment, and then delivers it in high power bursts for data collection and transmission. The below paper outlines innovative power architectures, showing designers how to use a single-cell CAP-XX supercapacitor rated at 2.7V in conjunction with a 3V energy source, instead of a larger and costlier dual-cell supercapacitor rated at 3V or more. Using a single-cell supercapacitor also reduces the leakage current of the power solution, thereby increasing battery life and reducing energy losses from environmental harvesting modules.
The technical paper is available at http://www.cap-xx.com/news/news.htm#InTheNews
This is a part that was mentioned in one of the comments on my blog. This transceiver from Zarlink Semiconductor specifies very low power operation. Has anyone worked with it?
Atmel has released a new RF transceiver for low power wireless applications. The AT86RF212 800/900MHz IEEE 802.15.4 radio has a receive mode current consumption of 9mA and 17mA in transmit mode with a power output level of 5dBm. The sleep mode current consumption is down to 0.2µA. The AT86RF212 performs extremely well, initial field test showed about a 6km link without the use of any external LNA’s or PA’s. A wide range of data rates are supported. In addition, security is handled by an AES 128bit onboard hardware engine. Atmel has created some common firmware solutions making it easier and faster to develop new applications. Take a look at the datasheets for full specs:
Freescale has partnered with design house Nuvation and is giving low power training experience. The seminars will help you reduce your power consumption, BOM cost, time–to–market. Design engineers looking for practical techniques for balancing the design challenges of portable product development are especially encouraged to attend. An understanding of embedded system design and “C” programming is beneficial.
Please take a look to check the locations and dates of the seminars:
TI has released the eZ430-RF2500-SEH development kit which incorporates the Cymbet EnerChip EH Solar Energy Harvesting module. The kit enables designers to create and operate an autonomous wireless sensor network right out of the box. All of the hardware, firmware and graphical user interface software are included in the kit. It looks like a great starting point for developing maintenance free sensor networks.
The Phoenix Processor developed by researchers at the University of Michigan can run on a watch battery for 263 years. The processor uses 10 times less power than comparable chips when active and 30,000 times less power in sleep mode. The processor is designed for sensor-based devices. Some applications include medical implants, environment monitors, structural integrity of buildings and bridges. The overall design was based around reducing sleep mode power consumption since in most application the sensor is a sleep 99 percent of the time. The processor runs on 0.5 Volts and in sleep mode consumes 30 picowatts. This is a very exciting development, which could open up the door for electronics to be used in applications that are currently purely mechanical due to the inconvenience of replacing batteries.
For more info: Phoenix Processor
When it comes to low-noise and low power microphone amplifiers Maxim is probably going to be on top of your list. The MAX9812 and MAX9813 amplifiers come in tiny packages and feature a 230uA supply current and only 100nA in shutdown mode. These amplifiers are great for compact applications such as cell phones. The specs include a 500kHz bandwidth, Rail-to-Rail® outputs, 100dB power-supply rejection ratio, a very low 0.015% THD + N, and a 20dB fixed-gain configuration that eliminates the need for external gain-setting components. They are available in a 2.7V to 3.6V range for PDA and cell phone applications and a 4.5V to 5.5V range for notebook and PC applications.
TI has introduced a few new DSP modules that were designed to increase battery life in a variety of electronics. For example the 674x DSP which targets audio, medical and industrial applications consumes one third the power of its competitors. Using 6 mW of power in sleep mode and 420 mW in active mode the chip adds to battery life while maintaining performance. The 640xDSP uses about half the power of its competitors and is designed for software-defined radio and other industrial instrumentation. The 550xDSP is the most exciting which uses only 6.8 uW in sleep mode and 46 mW in active mode. It targets music recording, noise-reduction headphones and multi-parameter medical applications.
The IEEE is organizing a conference that will allow for the exchange of ideas amongst experts from a broad range of disciplines on the technology, policy and economic framework required for the creation of a global sustainable energy infrastructure by 2030. The conference is going to be held on November 17th and 18th in Atlanta.
Some of the topics of interest are:
Reduced Carbon Generation
Reducing Energy Consumption
Replacing Fossil Fuel Consumption at the Load Point
Smart Grid and Power Delivery
Cymbet Corporation is a green technology company which specializes in thin-film batteries and energy harvesting technologies. The company has recently reviled the world’s first thin-film battery with integrated battery management. The EnerChip™ CC CBC3112 and CBC3150 thin-film batteries combine the Cymbet EnerChip with battery control logic in a single surface package. The package encompasses a thin-film battery, charge pump with integrated DC to DC converter, supply supervisor, low-ripple charger, configurable switchover to battery when input power fails, supply voltage status signals, and operation from 2.5 Volts to 5.5 Volts. The EnerChip CC CBC3112 is a 12µAh device and the CBC3150 is a 50µAh device. The EnerChip CC devices are packaged in either 7mm x 7mm or 9mm x 9mm DFN surface mount, reflow tolerant packages. The EnerChip CC has >5000 recharge cycles, low self-discharge, stable output voltage, and does not require a socket or holder which improves product reliability. This solution is an ideal replacement for supercapacitors and coin cells. A single EnerChip CC can manage multiple external EnerChips for high-capacity applications up to 500µAh. This is great technology which along with energy harvesting will bring us a step closer to smaller self reliant electronic devices.
Ultra quiet and using 75% less energy than a standard PC, VeryPC’s GreenPCs are a step in the right direction. These computers offer extremely high performance while being environmentally friendly. For instance, the Fulwood computer is a 16 Watt dual-cored media center PC which includes an Intel P9500 2.53GHz dual core CPU, 2GB RAM, 250GB HDD, Intel x4500HD graphics, DVDRW and surround sound audio. The system runs at an impressive 16Watts idle for the base model, 19Watts idle with all the available upgrade options, and only 2Watts in ‘sleep mode’. These PCs bring you the functionality and computer power you need while saving you money by using up to 5 times the energy of a normal PC. Moreover, the systems are made with the minimum amount of raw materials and have increased recyclability. I think this company is taking the right approach in their strategy and I hope that similar companies will begin to emerge.
Texas Instruments is offering a one day Power Supply Design Seminar. The content is both technical and practical. The seminar is good for engineers just beginning their careers, experienced power supply design engineers and engineering managers responsible for the power supply portion of the system/application. The main focus of the seminar is on the techniques of practical power supply design. The seminar is offered all over America and will also be coming to Asia and Europe.
Topics for the 2008 Seminar Series Include:
High Power Factor or High Efficiency… You CAN have Both
Reducing EMI from SMPS by Applying Spread Spectrum Techniques
High-Voltage Energy Storage – The Key to Efficient Hold Up
Under the Hood of DC/DC Boost Converter Design
Improving System Efficiency with a New Intermediate Bus Architecture
Using a PMBusTM for Improved System-Level Power Management
New Advances in Digital Power Control
New Product Review
Texas Instrument’s power supply engineers have a great amount of experience and are considered to be Gurus worldwide. I’m sure that this seminar will be very beneficial for anybody working with power supplies.
This is a site where you can view some of the talks given at the Emerging Communications Conference in Silicon Valley (2008). A lot of the talks are focused around innovation and the direction technology is moving in. The reason I’m posting this on this blog is because you will notice that a lot of the speakers mention how important low power consumption is becoming in advancing technologies. Please take a look, because there are some excellent talks by some of the leading people in technology.
AdaptivEnergy offers a demonstration kit that can harvest energy to power a microcontroller and a low power radio, this is a perfect combo for sensor networks. AdaptivEnergy’s piezoelectric harvester is said to allow up to ten times more strain to be applied to the piezoceramic than competing piezoelectric energy harvesting devices. The kit comes with a chipset consisting of a low power MSP430F2274 microcontroller and a CC2500 RF transceiver. This breakthrough in energy harvesting makes it a lot more feasible to have maintenance free smart sensor networks. Take a look at the product brief for more information.
The new MSP430F5xx family of microcontrollers from Texas Instruments run faster and are more configurable than previous versions of the MSP430. If used correctly the 16-bit RISC microcontrollers can by far be the lowest power solution for an embedded system.
The low power features include:
-25MHz core speed
-160µA/MHz
-A Power Management Module (PMM), varying the voltage from 1.4V to 1.9V in four steps
-A Unified Clock System with fail-safe clock operation
-Up to Eight DMA channels
-32-bit Real Time Clock (RTC) for extended sleep times
-Core off with peripherals running draws a mere 2µA
-A RAM and Status retention mode of 1µA
-Programmable GPIO drive levels
-An improved A/D with higher performance and lower current consumption
-Ability to turn different RAM sectors on or off to conserve power
-Read/erase/write of the Flash is possible at voltages down to 1.8V
-Up to 256KBytes Flash
-Up to 16KBytes RAM
Additional features include a hardware 32×32 multiply, a 4-wire JTAG interface, and integrated pull-up and pull-down resistors on GPIO pins.
Check out the video for more information:
MSP430F5XX Video
Texas Instrument’s low power RF group publishes an eNewsletter with the latest news releases, new product information and developers news to help you stay up to date with their RF solutions. The eNewsletter has useful links to user’s guides, design notes and other great information to help you with your RF design. The subscription is free so go check it out.
On June 10th 2008, Green Peak Technologies launched a new ultra low power communication controller. The Emerald GP500C is an IEEE 802.15.4 standard compliant chip which is designed to be coupled with energy harvesting devices in wireless sensor networks. The GP500C is a standards compliant communications controller that incorporates a transceiver with a fully integrated communications layer and an on-chip energy manager. The device is able to drive and control the data without being driven by a microcontroller cutting down on overall system power consumption. The GP500C consumes a fraction (10-25%) of the energy of traditional microcontroller based designs and has a system sleep mode of below 100nA. This is a great step forward for developing battery free sensor networks.
Using a low power digital light sensor could help extend battery life for applications with power hungry displays. By automatically adjusting the dimming of a display based on the ambient light conditions, one can reduce the overall power consumption of the device. For this type of system, Intersil has great low power digital light sensors that allow access to information through a standard I²C interface. The ISL29010 and ISL29013 sensors measure and digitize the value of ambient light providing a simple way of integrating dynamic dimming into a device. These sensors are flexible and easy to use and allow you to choose the dynamic range and low-light sensitivity for your specific application. The supply current is 250µA however a power-down mode exists which only draws 1 µA. With some smart software control, these sensors can really make a difference in power consumption.
Microchip Technology claims to offer the lowest power 16-bit microcontroller which has a standby current of just 100nA. The PIC24FJ256GB1 family of microcontrollers include an integrated USB 2.0 peripheral and up to 256kbyte flash and 16kbyte RAM on-chip. Capacitive touch user interface designs are supported by an integrated charge time measurement unit and the supplier’s royalty-free mTouch Sensing Solution software development kit. The pricing for the device starts at $3.47 each in 10,000 unit quantities. This is very exciting news for anyone who is working on a battery powered embedded application.
Researchers at HP Labs have demonstrated the existence of a fourth basic element in integrated circuits know as a memristor. Systems utilizing the memristor’s capability of memory retention without power could make it possible to develop far more energy-efficient computing systems. Memristor-based computers would not require the energy consumptive process of booting up, instead they would turn on instantly using less power and possibly increasing system resiliency and reliability. They would be perfect for applications that require a lot of memory without a lot of battery-power drain. A mathematical model and a physical example that prove the memristor’s existence appear in a paper published in the April 30 issue of the journal Nature.
If your design has the right condition, a multiple Vdd design could save you a bunch in power consumption. The basic idea behind having multiple power supplies is to lower the operating voltage of appropriate logic gates which naturally will cut down on the power dissipation through those gates. The gates that operate from the lower voltage pay the price of becoming slower. So the trick is to find the appropriate logic paths in your design that are not time constrained. For example if you have two logic paths operating simultaneously one consisting of 4 gates and the other of 8 and the result of both is needed to continue operations, the path with 4 gates is a perfect candidate for scaling its voltage. You can lower that path’s voltage supply effectively slowing it down, which in this case does not make a difference in the overall design since the outcome of the 8 gate path has to be processed anyway. There are many reasons for not slowing the whole logic system down but one to consider is that in most (not all) cases it is good to get things done quickly and go back to sleep or low power mode. Since we can not slow down the whole system there is a need for multiple power supplies. There are however overheads with this, for instance you will need level shifters when two different voltage level logic paths converge into a new logic function, and obviously there are costs in designing two different power supplies. However if power consumption is the underlining design specification, this technique can help.
Power Forward Initiative (PFI) has a publication of “A Practical Guide to Low-Power Design – User experience with CPF.” The guide provides examples of low power design using the Silicon Integration Initiative (Si2)-standard Common Power Format (CPF) in a holistic low-power design environment. This is a guide for integrated circuit (IC) designers and will help efficiently achieve the best possible power savings with a minimal learning curve.
Altair Semiconductors have developed what they claim is the world’s smallest and most power-efficient mobile WiMAX processor. The ALT2150 uses 142mW for a 1Mbps FTP upload, 125mW for a Streaming H.264 video, 81mW – VoIP call and 98mW in standby mode which is about half the power that is used by the competition. The chip implements full Wave-2 physical and Media Access Control (MAC) functionality. Altair’s product strategy exclusively focuses on battery operated devices and this is the reason for its excellent efficiency. Check out their webpage for more information.
