The Kynix Blog

  Do you know Dallas Semiconductor which is owned by Maxim Intergrated now? It's well known for making some excellent real-time clocks(RTCs). Let me take an example: DS1307 is simple,works with essentially any cheap 32,768Hz watch crystal,is easily accessible over I2C,and is extremely power efficient( 500nA current when running the oscillator on battery power). As great as it is, the DS1307 has a major drawback: it relies on an external crystal and lacks any sort of temperature compensation. Thus, any change in temperature will cause the clock to drift. A 20ppm error in the frequency of the crystal adds up to about a minute of error per month. Not so great. Well,it does not matter. It's fortunate that Maxim offers DS3231 which is called as an “Extremely Accurate I2C-Integrated RTC/TCXO/Crystal”.This chip has 32kHz crystaql integratrf into the package itself and uses a built -in temperature sensor to periodically measure  the temperature of the crystal and, by switching different internal capacitors in and out of the crystal circuit, can precisely adjust its frequency so it remains constant. It’s specified to keep time within 2ppm from 0°C to +40°C, and 3.5ppm from -40°C to +85°C, which means the clock would only drift 63 and 110 seconds per year, respectively. So cool. The one (very minor) downside is that it draws about twice the current, a bit less than 1 μA, than the DS1307. Still, a common 220mAh CR2032 battery could power the chip for at least a decade with no problem. Such a circuit would be mostly limited by the CR2032’s self-discharge rate anyway. In my case, I wanted to use such RTCs on several of my Raspberry Pis that are not regularly (read: almost never) connected to the internet, and so cannot always get their time from NTP servers. Some great people have designed a simple board that fits on the Raspberry Pi's pin headers for power,ground and I2c and own the DS3231,pull-up resistors for the I2C bus, and a decoupling capacitor. It even has pads for a backup battery (not included, but adding a battery holder and coin cell is straightforward). Chinese vendors on eBay sell the board for about $1.50, with free shipping. Perfect. The above picture is the board I am using on my Pis,along with the backup battery and holder I added. Well,I think this condition should be considered in that DS3231 is more expensive than a complete board.Well, I am so curious and I wondered if these were counterfeit chips that were pin and function compatible, QC rejects, or somehow otherwise illegitimate chips. For science, I ordered a few extra boards and tested them over the last year, where “tested” means “set the time on the chips with a Pi that was NTP synchronized to a GPS timing receiver, disconnected them from the Pi, and left them on the shelf running on battery power for a year”. The chips would be in direct sunlight in the mornings, and the temperature in the room would range between about 15°C and 30°C throughout the year. Not extreme, but not precisely regulated either. I did not adjust the “aging register” in the chip to trim the oscillator before this test, and the register was set to its default value of “0”. After a year, the chip with the largest drift was only 16 seconds off, which is about 0.5 ppm. That’s well within spec, so I’m happy. If these chips were counterfeit, they were at least good counterfeits that worked as advertised. However, I wanted to look closer so I sacrificed one of the chips for science. Thanks to my friend Jesse for reminding me that I can just snip off the legs of the chip rather than trying to de-solder it. That made things a lot easier. Here’s the top of the package. It claims to be an SN model, which means it is specced for the full -40°C to +85°C temperature range. The date code says it was made in week 33 of 2011, as part of lot 917AC. The # mark means it’s RoHS compliant. The laser markings seemed a bit dodgy and not like the normal high-quality laser markings I see on other Maxim chips. I contacted Maxim, explained the situation, and sent photos of the package and die (see below). After checking their records, they say the style of the markings, the date code, and lot number are all consistent with that particular lot made in 2011, which strongly suggests the chips are legitimate. They also reminded me that they do not warrant or guarantee any products purchased from unauthorized resellers! ! !( Buy DS3231 chip,go to kynix )Good to know, and not unexpected. I zoomed in with my USB microscope to examine the markings in more detail. It’s a bit hard to see in this close-up, but you should be able to see the digits “31”. Obviously, Maxim must have different types of laser marking equipment on their different production lines.  I normally would digest the epoxy packaging of the chip in acid at work, butI was at home that day and didn’t have access to the chemicals and safety equipment I have in the lab at work, plus I didn’t want to dissolve the integrated crystal and its metal can. Instead, I embrittled the packaging by heating it in the flame of a common Bic lighter for several seconds and then quenching it in a glass of cool water. I repeated this process several times. Next, I sanded down the back of the ship (assuming that the interesting parts of the die would face upwards, which they were — if they hadn’t been on the top, I’d sacrifice another chip and sand the top down) with fine sandpaper until I hit metal. It turns out I was a bit too vigorous in my sanding, and accidentally sanded through the crystal’s metal housing and broke one of the forks of the tuning fork oscillating element.Oops. In the photos below, the notch on the chip is to the left, so pin 1 is to the top left. The main die is behind the large copper pad to the left. The fuzzy “hair” at the bottom are strands of the epoxy package that I didn’t clean up.  Let's do a comprehensive observation. This was interesting, but even after Maxim said the packing and exterior markings looked legitimate, I was curious if the die itself was an actual Dallas/Maxim die or if it was a fake. Using tweezers and a fine, sharp knife I was able to crumble away more of the epoxy package and remove the die. Unfortunately, the bond wires were still embedded in the package and so broke off when I removed the die. I also slightly scratched part of the die and cracked off part of the top-right corner. Clearly, acid digestion is the way to go. Here’s the first look at the die itself. I had washed it with isopropanol and both the chip and the microscope slide are a bit wet. The die measures ~3.6 x 2.3 mm, and the images below were taken with my USB microscope.    First, I wanted to check to see if the die was actually made by Maxim or if it was a fake. The die clearly says “DALLAS SEMICONDUCTOR”, as well as “©2004 (M) MAXIM”. Looks legit. That’s refreshing.  In addition to my cheap USB microscope at home, I was later able to take the die into the lab at work and use the (very expensive) Zeiss microscope to take more pictures. I was also able to clean it more thoroughly using the ultrasonic cleaner so the images came out considerably better. Alas, compatibility issues between the camera mounted on the microscope and my computer prevented me from using the camera to get high-quality photos at this time. I’ve ordered an adapter so I can get better photos, but it will be several weeks. At that time I will either update this post or link to a new one. I plan on creating large composite images of the die at various levels of zoom, and with different optical filters. In the interim, here are a few photos I took using my smartphone aimed through the eyepiece of the lab microscope. They are nowhere near as clear or stunning in appearance as they are when viewed directly through the eyepiece or via the on-scope camera.  One days ago.I’ve been able to get the camera on the microscope to cooperate and have gotten several high-quality photos. As the microscope has an extremely short depth of focus, particularly at high magnification, some images have been “focus stacked” by combining several images at different focus depths. Similarly, the large composite images are made from several individual images that may be focused slightly differently from each other. These processes may cause visual artifacts to be present.  In general, images with green and red colored layers use standard reflected microscopy with no filters, while images with blue and gold layers use reflected differential interference contrast (DIC). That's all. Hope you like this observation about DS3231 real-time clock as me. 

There is no doubt that the use of LCD headlamp is a succcessful further step towards digitalizing lighting. LCD headlamp which enables complex functions will also be relevant to autonomous driving. Let's talk something about the following research project about developing a headlamp basics on a LCD (  Full name is Liquid Crystal Display )which made by HELLA and seceral partners.This technology is an good example already known in the home entertainment field.  About The ProjectIn the context of the research project funded by the Federal Ministry of Education and Research (BMBF) regarding the fully adaptive light distribution for intelligent, efficient and safe vehicle lighting (VoLiFa2020), HELLA has developed a headlamp on the basis of a Liquid Crystal Display (LCD) in collaboration with project partners Merck, Institut für Großflächige Mikroelektronik IGM, Stuttgart University, Porsche, Elmos Semiconductor, Schweizer Electronic, and the University of Paderborn. Complex FunctionsIn general,the new LCD headlamp projects 30.000 pixels onto the road. This allows adjusting the light pattern in an intelligent and continuous manner to various driving situations in real time. The use of an LC display is a further step towards digitalizing lighting. This means: the adaptation of the light pattern will increasingly be determined by software. The driver will obtain the best possible view of the road. Individual segments with e.g. other traffic participants or strongly reflecting street signs can be omitted or dimmed in a targeted manner. Highly complex functions are also conceivable: navigation arrows or lines showing the ideal lane can be projected onto the road. LCD technology enables functions that will also be relevant to autonomous driving.  The LC display is the headlamp’s key component. It is situated between the LED light source and the projection lens. The display generates a matrix with 100 x 300 pixels that can be individually controlled and dimmed. A camera installed in the vehicle as well as a sensor optically reading distances and speeds (light detection and ranging sensor, LiDAR), will forward the ambient information to the headlamp control unit via a processor. This will then direct the individual display pixels up to 60 times per second. 25 high-power LED’s arranged in three rows will serve as light source. Each LED’s light intensity will be adjusted to the respective lighting situation. Due to increasing traffic volumes and safety requirements, intelligent lighting systems are of increasing importance. LCD technology enables completely new functionalities and opportunities here. And the use is not limited to passenger cars. Other vehicle categories, such as commercial vehicles or buses also provide meaningful application areas. ThanksgivingThanks to this project's great resolution and sharpness of detail, it opens up a diffirent new paths in automotive lighting technology. 

Have you heard of Silicon carbide power devices yet? Researchers are rolling out a new manufacturing process and chip design for silicon carbide (SiC) power devices, which can be used to more efficiently regulate power in technologies that use electronics. The process -- called PRESiCE -- was developed to make it easier for companies to enter the SiC marketplace and develop new products.(Silicon carbide power devices, like the one shown here, are more efficient than their silicon counterparts.)"PRESiCE will allow more companies to get into the SiC market, because they won't have to initially develop their own design and manufacturing process for power devices -- an expensive, time-consuming engineering effort," says Jay Baliga, Distinguished University Professor of Electrical and Computer Engineering at NC State and lead author of a paper on PRESiCE that will be presented later this month. "The companies can instead use the PRESiCE technology to develop their own products. That's good for the companies, good for consumers, and good for U.S. manufacturing." Power devices consist of a diode and transistor, and are used to regulate the flow of power in electrical devices. For decades, electronics have used silicon-based power devices. In recent years, however, some companies have begun using SiC power devices, which have two key advantages. First, SiC power devices are more efficient, because SiC transistors lose less power. Conventional silicon transistors lose 10 percent of their energy to waste heat. SiC transistors lose only 7 percent. This is not only more efficient, but means that product designers need to do less to address cooling for the devices. Second, SiC devices can also switch at a higher frequency. That means electronics incorporating SiC devices can have smaller capacitors and inductors -- allowing designers to create smaller, lighter electronic products. But there's a problem. Up to this point, companies that have developed manufacturing processes for creating SiC power devices have kept their processes proprietary -- making it difficult for other companies to get into the field. This has limited the participation of other companies and kept the cost of SiC devices high. The NC State researchers developed PRESiCE to address this bottleneck, with the goal of lowering the barrier of entry to the field for companies and increasing innovation. The PRESiCE team worked with a Texas-based foundry called X-Fab to implement the manufacturing process and have now qualified it -- showing that it has the high yield and tight statistical distribution of electrical properties for SiC power devices necessary to make them attractive to industry. "If more companies get involved in manufacturing SiC power devices, it will increase the volume of production at the foundry, significantly driving down costs," Baliga says. Right now, SiC devices cost about five times more than silicon power devices. "Our goal is to get it down to 1.5 times the cost of silicon devices," Baliga says. "Hopefully that will begin the 'virtuous cycle': lower cost will lead to higher use; higher use leads to greater production volume; greater production volume further reduces cost, and so on. And consumers are getting a better, more energy-efficient product." The researchers have already licensed the PRESiCE process and chip design to one company, and are in talks with several others. "I conceived the development of wide bandgap semiconductor (SiC) power devices in 1979 and have been promoting the technology for more than three decades," Baliga says. "Now, I feel privileged to have created PRESiCE as the nation's technology for manufacturing SiC power devices to generate high-paying jobs in the U.S. We're optimistic that our technology can expedite the commercialization of SiC devices and contribute to a competitive manufacturing sector here in the U.S.," Baliga says. The paper, "PRESiCE: PRocess Engineered for manufacturing SiC Electronic-devices," will be presented at the International Conference on Silicon Carbide and Related Materials, being held Sept. 17-22 in Washington, D.C. The paper is co-authored by W. Sung, now at State University of New York Polytechnic Institute; K. Han and J. Harmon, who are Ph.D. students at NC State; and A. Tucker and S. Syed, who are undergraduates at NC State. The work was supported by PowerAmerica, the Department of Energy-funded manufacturing innovation institute that focuses on boosting manufacturing of wide bandgap semiconductor-based power electronics. ref.KY56-PZTA06KY41-SL12T1G

A team of University of Wisconsin-Madison engineers has created the most functional flexible transistor in the world -- and with it, a fast, simple and inexpensive fabrication process that's easily scalable to the commercial level. It's an advance that could open the door to an increasingly interconnected world, enabling manufacturers to add "smart," wireless capabilities to any number of large or small products or objects -- like wearable sensors and computers for people and animals -- that curve, bend, stretch and move. Transistors are ubiquitous building blocks of modern electronics. The UW-Madison group's advance is a twist on a two-decade-old industry standard: a BiCMOS (bipolar complementary metal oxide semiconductor) thin-film transistor, which combines two very different technologies -- and speed, high current and low power dissipation in the form of heat and wasted energy -- all on one surface. As a result, these "mixed-signal" devices (with both analog and digital capabilities) deliver both brains and brawn and are the chip of choice for many of today's portable electronic devices, including cellphones. "The industry standard is very good," says Zhenqiang (Jack) Ma, the Lynn H. Matthias Professor and Vilas Distinguished Achievement Professor in electrical and computer engineering at UW-Madison. "Now we can do the same things with our transistor -- but it can bend." Ma is a world leader in high-frequency flexible electronics. He and his collaborators described their advance in the inaugural issue of the journal Flexible Electronics. Making traditional BiCMOS flexible electronics is difficult, in part because the process takes several months and requires a multitude of delicate, high-temperature steps. Even a minor variation in temperature at any point could ruin all of the previous steps. Ma and his collaborators fabricated their flexible electronics on a single-crystal silicon nanomembrane on a single bendable piece of plastic. The secret to their success is their unique process, which eliminates many steps and slashes both the time and cost of fabricating the transistors. "In industry, they need to finish these in three months," he says. "We finished it in a week." He says his group's much simpler high-temperature process can scale to industry-level production right away. "The key is that parameters are important," he says. "One high-temperature step fixes everything -- like glue. Now, we have more powerful mixed-signal tools. Basically, the idea is for flexible electronics to expand with this. The platform is getting bigger." Ref.KY56-2SA1860KY45-EKMC1601113

Today I want to share an LED strobe design project I found in electronic-lab, which you can do it by yourself. Strobe provides regular flashes of light. Usually Strobes are designed using Xenon Tubes. Here is LED based simple solution that can be used as strobe for entertainment and events and also as warning signals. Project is based on PIC16F1825 micro-controller with two digit frequency display. Project provides TTL output signal, frequency 1Hz-25Hz, Tact switches provided to set the frequency. This project works along with DC Output Solid State Relay Features 1.Supply 4.5 to 5V DC2.Frequency 1Hz To 25Hz3.Easy Interface with Relay Board4.Easy Interface with Solid State Relay5.On Board Power LEDOn Board Output LED6.Onboard Switch to set the frequency7.2X7 Segment 0.5 Inch Display Applications 1.Strobe for Entertainment2.Traffic Signal3.Warning Signal4.Ambulance Warning Signals Schematic   Parts List Connections Photos Working Diagram Ref.PIC16F1825 

A Tomsk Polytechnic University study reveals how topological vortices found in low-dimensional materials can be both displaced and erased and restored again by the electrical field within nanoparticles. This may open exciting opportunities for memory devices or quantum computers in which information will be encrypted in the characteristics of topological vortices.(Vortices in nanoparticles exposed by the electrical field. Credit: Tomsk Polytechnic University (TPU))Scientists from TPU and international collaborators have discovered unusual self-organization of atoms in the volume of nanoparticles and have learned to control it via an electric field. Such controlled nanoparticles can be used to generate capacious non-volatile random access memory (NRAM), quantum computers and other next-generation electronics. The main author is Dmitriy Karpov, engineer of the Department of General Physics, TPU, who explains that in modern materials science, the defects of matter are divided into two large groups. The first group includes classical, well-studied defects, when atoms in matter are mechanically disordered, i.e., atoms are either removed or inserted into the lattice. In the other group, the spatial organization of the lattice itself changes and such defects are called topological. Topological defects can strongly influence matter, making it superfluid or superconductive, and therefore, it is very important to study them. Topological defects can be found only in low-dimensional materials—two-dimensional nanorods and nanofilms (just several atoms thick) and one-dimensional nanodots or nanoparticles, which are spherical particles consisting of several tens or hundreds of identical atoms. "One of the important topological defects is a topological vortex which looks like a discernible twisting caused by a small displacement of all atoms. The vortex core is a nanostrand which can be both displaced by the field, and erased and restored again within nanoparticles," explains Edwin Fohtung, Professor of Los Alamos National Laboratory and New Mexico State University . The scientists studied barium titanate nanoparticles whose internal structure was visualized with the help of penetrating X-ray radiation from the synchrotron Advanced Photon Source (Chicago, USA). They obtained an image of the volume of nanoparticles with a resolution of 18 nanometers, which enabled them to analyze the slightest changes in the structure. As a result, the researchers showed that an external electric field can displace the core of the topological vortex inside the nanoparticle, and when the field is removed, it returns to its original position. Modern components of electronics are gradually becoming smaller. This can significantly influence the efficiency of devices, which will be significantly reduced due to quantum effects. One way to circumvent these limitations is to use topological vortices. Thus, they can be used to generate high density NRAM or quantum computers in which information will be encrypted in the characteristics of topological vortices. "All in all, the possibility to control and adjust topological vortices in nanoparticles is important for the creation of new electronics," concludes Dmitriy Karpov. Further reading>>>Topological defectA topological defect can be proven to exist[when?] because the boundary conditions entail the existence of homotopically distinct solutions. Typically, this occurs because the boundary on which the conditions are specified has a non-trivial homotopy group which is preserved in differential equations; the solutions to the differential equations are then topologically distinct, and are classified by their homotopy class. Topological defects are not only stable against small perturbations, but cannot decay or be undone or be de-tangled, precisely because there is no continuous transformation that will map them (homotopically) to a uniform or "trivial" solution. Reference>>>KY259-BB910KY259-CXA1512MKY32-K9T1G08U0M-YIBO