The Kynix Blog

A small NO2 sensor featuring a low power consumption in the mW range has been developed by Imec and Holst Centre. The sensors have a low detection limit for NO2 (<10 ppb) and a fast response time. They are particularly well suited for air quality monitoring and serve as a solution to the increased demand for accurate local air quality monitoring for indoor and outdoor environments. The sensors are being tested in real-life situations, as part of an environmental monitoring platform.While wearable technology that measures body parameters has become increasingly popular in recent years, the Intuitive Internet of Things (I2oT) is next on the horizon: connecting everybody and everything everywhere with data stored in the cloud, turning the massive amount of data in information to make the right decisions, to take the right actions exactly as we need or want. The I2oT is expected to manage the sustainability, complexity and safety of our world. It will increase our comfort and wellbeing in many ways.Health issues resulting from poor air quality are a growing concern for consumers and accurate monitoring is becoming more and more in demand, for both outdoor and indoor environments.Air quality is typically measured on just a few distinct locations per city, with specialized equipment. Many current gas sensors are large in size, have high power consumption and are too cost prohibitive to be implemented on a large scale for I2oT applications. Imec and Holst Centre have developed small, simple, low power and high quality autonomous sensors that wirelessly communicate with the environment and the cloud.Imec and Holst Centre's NO2 sensors were integrated in the Aireas air quality network, a multiple sensor network in the city center of Eindhoven (the Netherlands). The purpose was to test -in actual outdoor conditions and long term- the stability of the sensors, and benchmark them against established reference sensors. The sensors are operational since early May 2015 and contribute with valuable outdoor sensor data since then. During traffic rush hours, the sensors detect a significant increase of NO2 concentration up to the health safety limits.Imec and Holst Centre are currently deploying a similar sensor network inside the Holst Centre building in Eindhoven to test the sensors for indoor air quality monitoring. This environmental monitoring platform today includes it proprietary NO2 sensor and commercial sensors for temperature, relative humidity and CO2. The measured levels can be monitored live, over the internet. In a next step, proprietary low-cost low-power sensors will be added for CO2, VOCs (Volatile Organic Compounds), ozone, and particle matter.The generated sensor data are transferred to the cloud, stored in a database and immediately available on (mobile) applications, explained Kathleen Philips, director of imec's perceptive systems for the intuitive internet of things R&D program. "Data fusion methodology and advanced algorithms enable us to combine data from different sensors such as temperature, several gasses, humidity, human presence detection and to derive contextual knowledge. This information contributes to a correct interpretation of the situation and helps us to take adequate actions to solve the problem. In this way, we have developed a context-aware intuitive sensing system."Companies interested in early application validation and development for distributed IoT networks and/or in the innovative technology and circuits to realize them are invited to become a partner in our R&D program. IP can also be licensed.

Imec and Holst Centre (set-up by imec and TNO) have demonstrated a prototype of a single-chip electrochemical sensor for simultaneous detection of multiple ions in fluids. The demonstrator paves the way to small-sized and low-cost detection systems for agriculture, healthcare and lifestyle applications, food quality monitoring and water management.Imec and Holst Centre's ion sensor solution is a generic platform that can be tailored towards specific applications. It enables efficient and low-cost monitoring, such as monitoring of nutrient concentrations in surface and waste water, both for agricultural applications and water quality. In the healthcare and lifestyle applications, it provides disposable point-of-care solutions, or conformable solutions for integration into patches. Depending on the application and the form factor, it can be mass produced through microfabrication or through screen-printing on inexpensive substrates such as glass or foil. As compared to commercial ion sensors, this bring a unique advantage in terms of low cost manufacturability, and size of the solution. Moreover, by changing the selective membranes on the electrodes, the sensor can be adopted to detect other ions.The presented prototype is a handheld device that integrates a single-chip sensor with different electrodes that detect pH levels in a range from 2 to 10 at a 0.1 pH accuracy. For the chemical elements chloride (Cl-), sodium (Na+), potassium (K+), and nitrate (NO3-) -ranging from 10-4 M to 1 M ions- the sensor detects at a 10 percent accuracy. Benchmarked against other available single-ion sensors, imec's prototype demonstrated comparable sensitivity and accuracy for a versatile multiple-ion solution."With small autonomous smart sensors that adapt to and wirelessly communicate with the environment and each other, imec aims to develop the building blocks that enable an Intuitive Internet of Things," stated Kathleen Phillips, program director perceptive systems at imec. "Our scientists and engineers have reached an important breakthrough demonstrating the capabilities of our technology with this versatile single-chip sensor. As we continue to improve our sensor platform, develop sensors for other ions, integrate more sensors into a single system, and extend the lifetime of our sensor, imec will be at the nucleus in driving the advancements of smart connected systems. We invite industry to join our R&D program, become a partner to jointly develop new ion sensing applications and to bring this technology to the market." 

Our modern world is based on semiconductors. In addition to your computer, cellphones and digital cameras, semiconductors are a critical component of a growing number of devices. Think of the high-efficiency LED lights you are putting in your house, along with everything with a lit display or control circuit: cars, refrigerators, ovens, coffee makers and more. You would be hard-pressed to find a modern device that uses electricity that does not have semiconductor circuits in it.While most people have heard of silicon and Silicon Valley, they do not realize that this is just one example of a whole class of materials.But the workhorse silicon – used in all manner of computers and electronic gadgets – has its technical limits, particularly as engineers look to use electronic devices for producing or processing light. The search for new semiconductors is on. Where will these materials innovations come from?What's a semiconductor?As the name suggests, semiconductors are materials that conduct electricity at some temperatures but not others – unlike most metals, which are conductive at any temperature, and insulators like glass, plastic and stone, which usually don't conduct electricity.However, this is not their most important trait. When constructed properly, these materials can modify the electricity moving through them, including limiting the directions it flows and amplifying a signal.The combination of these properties is the basis of diodes and transistors which make up all our modern gadgets. These circuit elements perform a multitude of tasks, including converting the electricity from your wall socket to something usable by the devices, and processing information in the form of zeros and ones.Light can also be absorbed into semiconductors and turned into electrical current and voltage. The process works in reverse as well, allowing for the emission of light. Using this property, we make lasers, LED lights, digital cameras and many other devices.The rise of siliconWhile this all seems very modern, the original discoveries of semiconductors date back to the 1830s. By the 1880s, Alexander Graham Bell experimented with using selenium to transmit sound over a beam of light. Selenium was also used to make some of the first solar cells in the 1880s.A key limitation was the inability to purify the elements being used. Tiny impurities – as small as one in a trillion, or 0.0000000001 percent – could fundamentally change the way a semiconductor behaved. As technology evolved to make purer materials, better semiconductors followed.The first semiconducting transistor was made of germanium in 1948, but silicon quickly rose to become the dominant semiconductor material. Silicon is mechanically strong, relatively easy to purify, and has reasonable electrical properties.It is also incredibly abundant: 28.2 percent of the Earth's crust is silicon. That makes it literally dirt cheap. This almost-perfect semiconductor worked well for making diodes and transistors and still is the basis of almost every computer chip out there. There was one problem: silicon is very inefficient at converting light into an electrical signal, or turning electricity back into light.When the primary use of semiconductors was in computer processors connected by metal wires, this wasn't much of a problem. But, as we moved toward using semiconductors in solar panels, camera sensors and other light-related applications, this weakness of silicon became a real obstacle to progress.Finding new semiconductorsThe search for new semiconductors begins on the periodic table of the elements, a portion of which is in the figure at right.In the column labeled IV, each element forms bonds by sharing four of its electrons with four neighbors. The strongest of these "group IV" elements bonds is for carbon (C), forming diamonds. Diamonds are good insulators (and transparent) because carbon holds on to these electrons so tightly. Generally, a diamond would burn before you could force an electrical current through it.The elements at the bottom of the column, tin (Sn) and lead (Pb), are much more metallic. Like most metals, they hold their bonding electrons so loosely that when a small amount of energy is applied the electrons are free to break their bonds and flow through the material.Silicon (Si) and germanium (Ge) are in between and accordingly are semiconductors. Due to a quirk in the way both of them are structured, however, they are inefficient at exchanging electricity with light.To find materials that work well with light, we have to step to either side of the group IV column. Combining elements from the "group III" and "group V" columns results in materials with semiconducting properties. These "III-V" materials, such as gallium arsenide (GaAs), are used to make lasers, LED lights, photodetectors (as found in cameras) and many other devices. They do what silicon does not do well.But why is silicon used for solar panels if it is so bad at converting the light into electricity? Cost. Silicon could be refined from a shovel full of dirt scooped up from anywhere on the Earth's surface; the III-V compounds' constituent elements are far rarer.A standard silicon solar panel converts the sunlight with an efficiency of 10 to 15%. A III-V panel can be three times as efficient, but often costs more than three times as much. The III-V materials are also more brittle than silicon, making them hard to work with in wide panels.However, the III-V materials' increased electron speeds enable construction of much faster transistors, with speeds hundreds of times faster than the ones you find in your computers. They may pave the way for wires inside computers to be replaced with beams of light, significantly improving the speed of data flow.In addition to III-V materials, there are also II-VI materials in use. These materials include some of the sulfides and oxides researched in the 1800s. Combinations of zinc, cadmium, and mercury with tellurium have been used to create infrared cameras as well as solar cells from companies such as First Solar. These materials are notoriously brittle and very challenging to fabricate.The future of semiconductorsHow might new semiconductor materials be used?High power III-V (gallium-nitride) semiconductor electronics will be the backbone of our electrical grid system, converting power for high voltage transmission and back again. New III-V materials (antimonides and bismuthides) are leading the way for infrared sensing for medical, military, other civilian uses, as well new telecommunication possibilities. Earth-abundant element combinations are being explored to make new semiconductors for high-efficiency, but inexpensive, solar cells.And what of the old standby, silicon? Its inability to harness light efficiently does not mean that it is destined for the dust bin of history? Researchers are giving new life to silicon, creating "silicon photonics" to better handle light, rather than just shuttling electrons.One method is the inclusion of small amounts of another group IV element, tin, into silicon or germanium. That changes their properties, allowing them to absorb and emit light more efficiently.The act of including that tin turns out to be difficult, like many other challenges in material science. But as I tell my students all the time, "if it were easy, then it would not be research."      

Fujitsu today announced the development of a gallium-nitride (GaN) high-electron mobility transistor (HEMT) power amplifier for use in W-band (75-110 GHz) transmissions.This can be used in a high-capacity wireless network with coverage over a radius of several kilometers. In areas where fiber-optic cable is difficult to lay, to achieve high-speed wireless communications of several gigabits per second, one promising approach is to use high-frequency bands, such as the W band, which uses a wide frequency band. In order to get good long-distance coverage in these frequencies, however, it is necessary to increase the output power of the power amplifier to the scale of watts. Fujitsu succeeded in developing a power amplifier for W-band transmissions using GaN-HEMT technology capable of high output at 100 GHz. Evaluations of the newly developed power amplifier confirmed it to have 1.8 times increased output performance than before, which would translate to an increase of over 30% in transmission range when used in a high-speed wireless network. A portion of this research was conducted as part of a project of the National Institute of Information and Communications Technology (NICT) on "Agile Deployment Capability of Highly Resilient Optical and Radio Seamless Communication Systems." Details of this technology are being presented at Power Amplifiers for Wireless and Radio Applications (PAWR2016), opening January 24 in Austin, Texas.High-frequency wireless communications, using the frequency band known as the W band (75-110 GHz), are drawing increasing interest, both as a way to temporarily set up high-capacity communications channels for handling special events where large numbers of people gather, or for responding to disasters, and also as a way to bring communications to remote areas where fiber-optic cables are difficult to lay. Compared to today's mobile phones, which use frequencies in the 0.8-2.0 GHz range, the W band uses a frequency band more than 50 times as broad with 50 times the speed, meaning it is a frequency band that is well-suited to these high-capacity wireless communications.In order to transmit wireless signals over a distance of several kilometers, the transmission antenna needs a power amplifier capable of a high output on the order of several watts. Existing power amplifiers for high-frequency transmissions in the millimeter-wave band (30-300 GHz), which are built using gallium arsenide or CMOS semiconductors, are limited by their operating voltage to an output of about 0.1 W, and it has not been possible to increase this. GaN-HEMT power amplifiers have achieved high output performance in the microwave range (3-30 GHz), but the problem up until now was that their output performance declined in the W-band range. To solve these problems, Fujitsu developed a GaN-HEMT device with a unique structure capable of increasing output in the millimeter band (Figure 1). This uses a layer of indium-aluminum-gallium-nitride (InAlGaN), and double-layer silicon nitride (SiN) passivation film to increase current density by a factor of about 1.4, resulting in 3.0 W of output power from a transistor per 1-mm of gate width, at a high frequency of 100 GHz. In developing this transistor, Fujitsu collaborated with Professor Yasuyuki Miyamoto of the Tokyo Institute of Technology in developing a device-simulation technology.Fujitsu succeeded in developing a power amplifier with the world's highest W-band output performance using this GaN-HEMT device with a proprietary structure (Figure 2). In order to successfully design a power amplifier with high output performance, Fujitsu precisely measured and modeled the characteristics of GaN-HEMT during high-frequency operation. Based on that, a circuit was designed where pairs of GaN-HEMTs were grouped together into compact, high-gain units with low power loss. In order to maximize the power from these units, GaN-HEMTs were connected in a series by the interstage circuit where the signal lines and the device layouts were carefully laid out. Using a model of these compact, high-gain units, Fujitsu conducted simulations to optimize the distributor and combiner matching circuits between the units, and their layouts and signal lines, resulting in a high-amplitude power amplifier (Figure 3). A prototype power amplifier had amplitude that multiplied its input by a factor of 80, producing 1.15 W of output power. Power output per transistor, a measure of power-amplifier performance, was 3.6 W per 1 mm of gate width, the highest in the world.The newly developed power amplifier achieved a 1.8 times increase in power-amplifier output over previous W-band power amplifiers, with the world's highest output performance (Figure 4). This translates to an improvement of over 30% in terms of range for wireless communications at speeds of several gigabits per second.Fujitsu plans to apply this power-amplifier technology to high-capacity long-range wireless communications, and to implement high-speed wireless communications systems that can be used for high-expediency temporary communications infrastructure for use during special events and when fiber-optic links have been broken in the event of disasters.  

Exar announces the XR77103 Universal PMIC, Exar's first Universal PMIC with three integrated synchronous MOSFET power stages.  This integration results in an even smaller solution than was possible before, a tiny, 4mm x 4mm IC which delivers an easy-to-use power management solution for a broad range of FPGAs, SoCs, DSPs and video processors.The XR77103 features an I2C interface allowing customers to control output voltage (from 0.8V to 6V), switching frequency (from 300kHz to 2.2MHz), power sequencing, and current limit. The XR77103 is supported by a new release of PowerArchitect™ 4 design and configuration software.The XR77103 operates from a 4.5V to 14V input supply and all three outputs are designed for 2A load currents with peak currents up to 3A.  Since the device employs a current mode control architecture, outputs can be easily paralleled to provide up to a total of 5A allowing the XR77103 to power a range of low power processors.  A selectable Pulse Skipping Mode (PSM) results in improved efficiency at light loads, a key feature in meeting standby energy requirements or extending battery life.As the device supports up to a 2.2MHz switching frequency and is packaged in a 4x4mm QFN, it requires fewer and smaller external components, saving engineers valuable board space in their next design.  This family also includes two versions of the XR77103 which offer a fixed set of features for designers not requiring the I2C interface. The XR77103ELB-A0R5 and -A1R0 are fixed at switching frequencies of 500kHz and 1MHz, respectively.  Both products feature a 0.8V, high accuracy reference (1%) and their output voltages are set by external resistors.The XR77103ELB, XR77103ELB-A0R5 and XR77103ELB-A1R0 are available in RoHS compliant, green/halogen free, space-saving 4x4 QFN packages.    

Jake Dyson, son of Dyson founder James, has staked out his corner in the engineering innovation world with a focus on LED solutions, the Jake Dyson Light. He has in turn been doing a rethink on the characteristics and function of a desk light. He proudly states his LED light solution goes past other designers who have tried to cool LEDs with "half-hearted" attempts. Jake said their lights were built to fail. Dyson and team have come up with a light that cools LEDs properly. Benefit to consumers? A light that lasts for 37 years. Conventional lights neglect to protect LEDs from heat, exposing them to temperatures of up to 130°C. This damages the LEDs' phosphorous coating and degrades brightness and color, said his site.His desk lamp solution: CSYS task lights -Operating at 55°C and making use of "heat pipe technology" the Dyson solution can direct heat away from the LEDs. They lose neither quality nor efficiency for 37 years.Eight LEDs provide 587lx of white light for 37 years. Each is in a conical reflector to eliminate glare.How does he know his product lasts for 37 years? The number was calculated based on IES TM-21-11, he said. The 37 years (or 160,000 hours) is based on 12 hours of continual use per day. (IES stands for Illuminating Engineering Society. TM-21-11 provides a method to determine when the useful lifetime of an LED is reached, a point when the light emitted from an LED depreciates to a level no longer considered adequate for a specific application.)What does he mean by heat pipe technology? "Heat is drawn away from the LEDs using technology typically found in satellites. It's dissipated through an aluminium heat sink, which forms the light's horizontal arm," according to the site.Looking back at how this was developed, he said the process involved looking at, analyzing, lighting. The key goal was not to design things that look good, he said, but to try to improve efficiency with engineering. He said he spent some months looking at problems with lighting, and the big problems that stood out were the lack of direction of light. The arm of the light was positioned by springs and pillars and those wear out over time, he said. So wherever you position your light, it would drop.Dyson initiated a mechanism —the light moves up and down and rotates and moves in and out. Where you position the mechanism for light is where it is. The LEDS were also repositioned for an even spread of light.His site said whereas "conventional lights rely on tension to stay in position, CSYS task lights use gravity." The arm moves vertically using a counterweight pulley system inspired by the construction crane. It extends 27.5 cm horizontally along anti-friction bearings. The zinc alloy base rotates through 360°, and is weighted to increase stability. One can position the light where required with the touch of a fingertip. It moves vertically, horizontally and rotationally through 360°. The LEDs use only a fifth of the energy of a conventional halogen bulb. The product prices are listed on the Dyson site.To cool LEDS is critical to the LED market, he said. Gizmag's Nick Lavars noted how "Efforts to keep LED bulbs cool has been a focus for manufacturers working to drag the technology into the mainstream. While LEDs won't get as hot as the incandescent cousins, they do still generate heat, which sees their brightness and color deteriorate over time."