The Kynix Blog

At last week's IEEE International Electron Devices Meeting (IEDM) in San Francisco (USA), imec, the world-leading research and innovation hub in nano-electronics and digital technology and Holst Centre debuted a miniaturized sensor that simultaneously determines pH and chloride (Cl-)levels in fluid. This innovation is a must have for accurate long-term measurement of ion concentrations in applications such as environmental monitoring, precision agriculture and diagnostics for personalized healthcare. The sensor is an industry first and thanks to the SoC (system on chip) integration it enables massive and cost-effective deployments in Internet-of-Things (IoT) settings. Its innovative electrode design results in a similar or better performance compared to today's standard equipment for measuring single ion concentrations and allows for additional ion tests.Sensors based on ion-selective membranes are considered the gold standard to measure ion concentrations in many applications, such as water quality, agriculture, and analytical chemistry. They consist of two electrodes, the ion-sensitive electrode with the membrane (ISE) and a reference electrode (RE). When these electrodes are immersed in a fluid, a potential is generated that scales with the logarithm of the ion activity in the fluid, forming a measure for the concentration. However, the precision of the sensor depends on the long-term stability of the miniaturized RE, a challenge that has now been overcome."The common issue with such designs is the leaching of ions from the internal electrolyte, causing the sensor to drift over time," stated Marcel Zevenbergen, senior researcher at imec/Holst Centre. "To suppress such leaching, we designed and fabricated an RE with a microfluidic channel as junction and combined it with solid-state iridium oxide (IrOx) and silver chloride (AgCl) electrodes fabricated on a silicon substrate, respectively as indicating electrodes for pH and Cl-. Our tests demonstrated this to be a long-term stable solution with the sensor showing a sensitivity, accuracy and response time that are equal or better than existing solutions, while at the same time being much smaller and potentially less expensive.""We are providing groundbreaking sensing and analytics solutions for the IoT," stated John Baekelmans, Managing Director of imec in The Netherlands. "This new multi-ion sensor is one in a series that Holst Centre is currently developing with its partners to form the senses of the IoT. For each sensor, the aim is to leapfrog the current performance of the state-of-the-art sensors in a mass-producible, wireless, energy optimized and miniaturized package."Reference:ADXRS620BBGZLPY410ALTRL3GD20HTR  

Researchers from the University of Twente MESA+ research institute, together with the company SolMateS, have developed a new type of transistor to reduce the power consumption of microchips. The basic element of modern electronics, namely the transistor, suffers from significant current leakage. By enveloping a transistor with a shell of piezoelectric material, which distorts when voltage is applied, researchers were able to reduce this leakage by a factor of five (compared to a transistor without this material). An article presenting the prototype of the transistor appears in the June issue of IEEE Transactions on Electron Devices, an authoritative scientific journal in the field of transistor research.Current leakage in transistors is one of the causes of battery depletion in portable electronic devices, such as smartphones and laptops. With the new type of transistor, either the current leakage (while the transistor is not active) or the energy consumption (while the transistor is active) can be addressed. In the latter case, it is estimated that energy consumption can be reduced by approximately 10%.Intelligent squeezingThe trick lies in a piezoelectric material which is applied to the exterior of the transistor. The piezoelectric material expands when you apply a voltage to it and compresses the silicon in the transistor with a pressure of about 10,000 atmospheres. This high pressure ensures that electrons flow through the transistor faster. You can therefore make microchips more efficient by 'intelligently squeezing the transistor'.Incidentally, existing transistors are already put under high pressure in order to improve their efficiency. In this case, however, the pressure is permanently built in, which actually increases the current leakage. In the prototype designed by the UT, the transistor is only put under pressure when required and this makes a big difference. The electric current needed to switch the transistor from on to off is thereby partly replaced by mechanical tension.CrudeAccording to dr. ir. Ray Hueting from the chair Semiconductor Components, this is an initial prototype that can already produce energy savings. "The design is still fairly crude where the material is concerned. With the further development of the transistor, it should therefore be possible to achieve a further significant increase in efficiency."The operating principle of this transistor was theoretically predicted in 2013 by the same research group. But in advance it was by no means certain that the transistor would be a success. The reason for this is that piezoelectric materials and silicon (which transistors are made of) are difficult to combine. The researchers solved this by inserting a buffer layer between the two materials.    

One of the greatest challenges in the evolution of electronics has been to reduce power consumption during transistor switching operation. In a study recently reported in Nature, engineers at University of California, Santa Barbara, in collaboration with Rice University, have demonstrated a new transistor that switches at only 0.1 volts and reduces power dissipation by over 90% compared to state-of-the-art silicon transistors (MOSFETs).     MOSFETs have been the building blocks of everyday electronic products since the 1970s. However, to sustain the ever-growing need for increased transistor densities, miniaturization of MOSFETs has given rise to a power dissipation challenge due to the fundamental limitations of their turn-on characteristics. "The steepness of a transistor's turn-on is characterized by a parameter known as the subthreshold swing, which cannot be lowered below a certain level in MOSFETs," explained Kaustav Banerjee, Professor of Electrical and Computer Engineering at UC Santa Barbara. A minimum gate voltage change of 60 millivolts at room temperature is required to change the current by a factor of ten in MOSFETs. In essence, the existing state of transistor technology limits the energy efficiency potential of digital circuits in general. The research group of Professor Kaustav Banerjee at UC Santa Barbara took a new approach to subverting this fundamental limitation. They employed the quantum mechanical phenomenon of band-to-band tunneling to design a tunnel field effect transistor (TFET) with sub-60mV per decade of subthreshold swing. "We restructured the transistor's source to channel junction to filter out high energy electrons that can diffuse over the source/channel barrier even in the off state, thereby making the off state current negligibly small," explained Banerjee. At UCSB, Banerjee's Nanoelectronics Research Lab includes Deblina Sarkar, Xuejun Xie, Wei Liu, Wei Cao, Jiahao Kang, and Stephan Kraemer, as well as Yongji Gong and Pulickel Ajayan of Rice University. Banerjee and his colleagues are motivated by a global electronics industry that loses billions of dollars each year to the impact of power dissipation on chip cost and reliability. "This translates into lower battery lifetime in personal devices like cell phones and laptops, and massive power consumption of servers in large data centers," adds Banerjee, pointing out the global scale of this energy demand. An industry that relies on conventional semiconductors such as silicon or III-V compound semiconductors as the channel material for TFETs, Banerjee explains, "faces limitations because these materials have high density of surface states, which increase leakage current and degrade the subthreshold swing." The TFET designed by the UCSB team overcame this challenge in a few ways, most significant being the use of a layered two-dimensional (2D) material called molybdenum disulphide (MoS¬2). As the current-carrying channel placed over a highly doped germanium (Ge) as the source electrode, MoS2 offers an ideal surface and thickness of only 1.3nm. The resulting vertical heterostructure provides a unique source-channel junction that is strain-free, has a low barrier for current-carrying electrons to tunnel through from Ge to MoS¬2 through an ultra-thin (~0.34nm) van der Waals gap, and a large tunneling area. "The crux of our idea is to combine 3D and 2D materials in a unique heterostructure, to achieve the best of both worlds. The matured doping technology of 3D structures is married to the ultra-thin nature and pristine interfaces of 2D layers to obtain an efficient quantum-mechanical tunneling barrier, which can be easily tuned by the gate," commented Deblina Sarkar, lead author of the paper and PhD student in Banerjee's lab. "We have engineered what is, at present, the thinnest-channel subthermionic transistor ever made," said Banerjee. Their atomically-thin and layered semiconducting channel tunnel FET (or ATLAS-TFET) is the only planar architecture TFET to achieve subthermionic subthreshold swing (~30 millivolts/decade at room temperature) over four decades of drain current, and the only one in any architecture to achieve so at an ultra-low drain-source voltage of 0.1V. Ajayan, co-author and professor of chemical and biomolecular engineering at Rice University, commented, "This is a remarkable example showing the uniqueness of 2D atomic layered materials that enables device performance which conventional materials will not be able to achieve. This is perhaps the first breakthrough in a series of novel devices that people will now aspire to build using 2D materials." "The work is a significant step forward in the search for a low voltage logic transistor. The demonstration of sub-thermal operation over four orders of magnitude is impressive, and the on-current also advances the state-of-the-art. There is still a long ways to go, but this work demonstrates the potential of 2D materials to realize the long-sought, low-voltage device," commented Mark Lundstrom, professor of electrical and computer engineering at Purdue University. "We have demonstrated how to achieve the most important metric of steep subthreshold swing that meets ITRS requirements. Our transistor can be utilized for a number of low-power applications including arenas where the steep subthreshold swing is the main requirement, such as biosensors or gas sensors. With improved performance, the range of applications of this transistor can be further expanded," explained Wei Cao, a PhD student in Banerjee's group and a co-author of the article. "This work represents an important step of bringing 2D materials closer to real applications in electronics. The use of 2D materials in tunneling transistors started only recently, and this paper gives the whole field yet another strong boost in improving the characteristics of such devices even further," commented Dr. Konstantin Novoselov, a professor of physics at University of Manchester. Novoselov was co-recipient of the 2010 Nobel Prize in Physics, awarded for the discovery of graphene. "When I first heard Banerjee's idea of using 2D materials for designing inter-band tunneling transistors in 2012, I recognized its merit and immense potential for ultra-low power electronics. I am pleased to see that his vision has been realized," commented James Hwang, professor of electrical engineering at Lehigh University, who was then the AFOSR program manager responsible for funding this research.    

IntroductionIn today's rapidly advancing world of semiconductor technology, ensuring effective overcurrent protection has become more important than ever. One standout solution is the PTC (Positive Temperature Coefficient) resettable fuse. These fuses, often referred to as polymeric positive temperature coefficient devices, offer the dual benefit of safeguarding electronic circuits while being reusable after tripping. Their unique ability to reset after a fault makes them a go-to option for many applications. This guide will take you through the fundamentals of PTC resettable fuses, shedding light on how they work, where they are most commonly used, their key advantages, and best practices for incorporating them into semiconductor designs. What is a PTC Resettable Fuse?A PTC resettable fuse is a thermally responsive device that works by significantly increasing its resistance when exposed to excessive current or temperature. This rise in resistance limits the current flowing through the circuit, providing essential protection to sensitive components and preventing potential damage. Once the fault is resolved and the device cools down, the fuse automatically resets, enabling the circuit to function as normal.At the heart of a PTC resettable fuse is a polymeric material embedded with conductive particles. Under standard conditions, these particles create a low-resistance path that allows current to pass through. However, when an overcurrent or overheating situation occurs, the polymer heats up and expands, causing the conductive particles to separate. This expansion leads to a sharp increase in resistance, reducing the current flow until the device cools and resets. Working PrincipleThe working principle of a PTC resettable fuse is rooted in its positive temperature coefficient characteristics. Here's a step-by-step breakdown:Normal Operation: Under normal conditions, the PTC resettable fuse exhibits low resistance, allowing current to pass through with minimal voltage drop.Overcurrent Event: When an overcurrent occurs, the temperature of the PTC material increases due to the higher power dissipation (P = I²R).Resistance Increase: As the temperature rises, the polymer matrix expands, causing the conductive particles to move apart, which dramatically increases the resistance.Current Limitation: The increased resistance significantly reduces the current flow, protecting the circuit components.Resetting: Once the overcurrent condition is removed and the device cools down, the polymer contracts, the conductive particles reconnect, and the resistance returns to its normal low value, ready to protect the circuit again. Key Applications of PTC Resettable FusesPTC resettable fuses are widely used across multiple industries due to their reliable protection and resettable features. Some of the most common applications include:1.Consumer Electronics: In devices like smartphones, tablets, and laptops, PTC fuses protect against potential overcurrent situations caused by short circuits, malfunctioning batteries, or power surges.2.Automotive Industry: With the growing complexity of automotive electronics, PTC fuses are essential for safeguarding vehicle circuits, particularly in protecting electronic control units (ECUs) and other critical components from overcurrent incidents.3.Telecommunications: In both wired and wireless communication systems, PTC fuses play a key role in preventing power surges and overcurrent issues that could disrupt or damage telecommunication devices.4.Industrial Control Systems: PTC fuses are frequently used in industrial settings to protect control circuits and sensors from overcurrent situations, ensuring consistent system operation and minimizing equipment downtime.5.Medical Devices: The reliability of medical equipment is crucial. PTC resettable fuses provide protection from overcurrent without compromising the continuous operation of life-saving devices, making them a trusted component in medical electronics. Advantages of PTC Resettable FusesPTC resettable fuses offer several key benefits that make them a preferred choice for various applications compared to traditional fuses and other protection devices:Resettable Functionality: Unlike conventional fuses that require replacement after a fault, PTC fuses reset automatically once the fault is cleared. This feature reduces maintenance costs and minimizes system downtime.Compact Size: Available in various sizes, including surface-mount options, PTC fuses can be easily integrated into small or space-constrained devices, making them ideal for modern compact electronics.Reliable Protection: PTC fuses effectively protect sensitive components from overcurrent and overtemperature events, ensuring the longevity and safety of electronic systems.Cost-Effective in the Long Run: Since PTC fuses are resettable, they eliminate the need for frequent replacements, making them a more cost-effective solution, especially in applications where fuse replacement is impractical.Wide Operating Range: These fuses can operate across a broad range of temperatures and current levels, providing flexibility in design and enabling their use in a variety of environments. Selecting the Right PTC Resettable FuseChoosing the appropriate PTC resettable fuse for your application involves considering several important factors:Hold Current (I_hold): This represents the maximum current the fuse can handle without triggering a rise in resistance. It should match or slightly exceed the circuit's normal operating current.Trip Current (I_trip): This is the current level at which the fuse starts to increase resistance. It should be selected based on the maximum tolerable current for the components being protected.Max Voltage Rating: Ensure the fuse can handle the highest voltage present in the circuit without breaking down.Time-to-Trip: The speed at which the fuse responds to an overcurrent situation is crucial. Faster response times are necessary for applications requiring immediate protection.Environmental Factors: Consider factors like temperature range, vibration, and humidity when selecting a fuse, as these can affect its performance.Form Factor: The physical size of the fuse should align with the design constraints of the device or system. Implementation Best PracticesTo ensure optimal performance, follow these best practices when incorporating PTC resettable fuses into your designs:Proper Placement: Install the fuse as close as possible to the components it protects to ensure a quick response to overcurrent events.Thermal Management: Maintain adequate cooling around the PTC fuse to prevent it from tripping due to high ambient temperatures rather than actual overcurrent conditions.Avoid Parallel Configurations: Using PTC fuses in parallel can result in uneven current distribution and unreliable protection. It should only be done if absolutely necessary.Testing and Validation: Thoroughly test the circuit with the PTC fuse under various fault conditions to ensure its reliability and effectiveness.Consult Manufacturer Guidelines: Always refer to the fuse manufacturer's datasheets for specific recommendations regarding proper use. Challenges and ConsiderationsWhile PTC resettable fuses offer numerous advantages, they come with certain challenges and considerations:Temperature Sensitivity: PTC fuses are highly sensitive to temperature variations, which can affect their performance. Careful attention must be paid to operating conditions.Limited Current Handling: These fuses are generally not suitable for high-current applications, as their current-carrying capacity is lower than traditional fuses.Potential for Nuisance Tripping: In environments with high ambient temperatures or fluctuating currents, PTC fuses may trip unintentionally. Proper selection and placement can help mitigate this issue.Recovery Time: After tripping, PTC fuses require time to cool down and reset. In some cases, this recovery time may result in temporary interruptions in device operation.Cost vs. Performance: While they are cost-effective over time, PTC fuses often have a higher initial cost than traditional fuses. Engineers must evaluate whether the long-term benefits justify the upfront expense for their specific application. Future Trends in PTC Resettable FusesAs the demand for more sophisticated protection solutions continues to grow, several trends are shaping the future development of PTC resettable fuses:Miniaturization: With devices becoming smaller, PTC fuses are being designed in increasingly compact form factors to fit within tight spaces.Integration with Smart Systems: The future may see PTC fuses integrated with smart features like remote diagnostics and monitoring, enabling predictive maintenance and enhancing system reliability.Enhanced Performance Materials: Advances in material science are resulting in PTC fuses with improved temperature stability, faster response times, and higher current ratings, making them suitable for a wider range of applications.Customization: Manufacturers are offering more tailored solutions, allowing engineers to specify PTC fuses that meet exact performance requirements, improving both protection and overall system reliability. ConclusionPTC resettable fuses have become an essential component for engineers working in the semiconductor industry, providing reliable and reusable overcurrent protection for a wide range of applications. By understanding their functionality, key applications, and implementation best practices, designers can enhance the safety, reliability, and cost-efficiency of their electronic systems.

In 2014, when University of Wisconsin-Madison engineers announced in the journal Nature Communications that they had developed transparent sensors for use in imaging the brain, researchers around the world took notice.Then the requests came flooding in. "So many research groups started asking us for these devices that we couldn't keep up," says Zhenqiang (Jack) Ma, the Lynn H. Matthias Professor and Vilas Distinguished Achievement Professor in electrical and computer engineering at UW-Madison.Ma's group is a world leader in developing revolutionary flexible electronic devices. The see-through, implantable micro-electrode arrays were light years beyond anything ever created.Although he and collaborator Justin Williams, the Vilas Distinguished Achievement Professor in biomedical engineering and neurological surgery at UW-Madison, patented the technology through the Wisconsin Alumni Research Foundation, they saw its potential for advancements in research. "That little step has already resulted in an explosion of research in this field," says Williams. "We didn't want to keep this technology in our lab. We wanted to share it and expand the boundaries of its applications."As a result, in a paper published Thursday (Oct. 13, 2016) in the journal Nature Protocols, the researchers have described in great detail how to fabricate and use transparent graphene neural electrode arrays in applications in electrophysiology, fluorescent microscopy, optical coherence tomography, and optogenetics. "We described how to do these things so we can start working on the next generation," says Ma.Now, not only are the UW-Madison researchers looking at ways to improve and build upon the technology, they also are seeking to expand its applications from neuroscience into areas such as research of stroke, epilepsy, Parkinson's disease, cardiac conditions, and many others. And they hope other researchers do the same."This paper is a gateway for other groups to explore the huge potential from here," says Ma. "Our technology demonstrates one of the key in vivo applications of graphene. We expect more revolutionary research will follow in this interdisciplinary field."Reference:GP1S036PKGS-00GXP1-RRB-3R0232-50  

LED technology has evolved as very efficient solution for all our lighting needs in our homes, offices, parking lots, industries, streets and many other areas. However the application of LED as LED Industrial light, LED flood light and LED parking light is the biggest revolution as it has cut down the energy requirement significantly and offered a very durable lighting option that can last for years without needing replacement. The use of LED in industries and streets offers a very high quality lighting solution at reasonable cost. In fact, the lifetime cost of LED turns out to be much lesser than the HID lighting, which is gradually being replaced by LED. One of the main reasons for lesser lifetime cost is the long life of LED with very low power consumption. LED lighting offers a very promising solution for our future as the cost of LED will continue to drop as it has in the last few years because of the improving manufacturing techniques providing more efficient and cost effective production of LED for industries. LED light systems, like LED flood light systems offer many advantages over traditional lighting. Some of them are as follows: 1.    Extremely low power consumption2.    Long Life of Lights leading to excellent life for overall system3.    Excellent ability of color rendering according to the application 4.    Higher initial cost but better lifetime cost as compared to any other option.LED industrial light not only offers a very efficient alternative but also an environment friendly options that will help us cut down on the critical carbon emissions leading to a better future for the upcoming generations. The main reasons that make LED Industrial Lighting a perfect solution are as follows:Long Life: In terms of life expectancy, LED lighting turns out to be 20 times better as compared to the incandescent bulbs. The average life of LEDs is about 60,000 hours whereas a normal incandescent bulb lasts for about merely 1500 hours on an average. When compared to fluorescent bulbs. LEDs last 10 longer which is still a significant difference.Low Power Consumption: When it comes to power, LEDs offer a very efficient option with extremely less power consumption. It is estimated that by using LEDs in US, about 348 terawatt hours of electricity can be saved which costs huge amount of $30 billion. Better Distribution of Light: LED Lighting offers much better focusing properties which results in better distribution of light in the desired direction as compared to other sources of light which throws the light in every direction resulting into wastage of energy. Reference:ASMT-UYBG-NACJ8XRCWHT-L1-0000-004E6LCWW5AM-KXKY-4U8X