FPGA chip cooling design

For any chip to work, it must satisfy a temperature range, which refers to the temperature on the silicon wafer, commonly referred to as junction temperature.

FPGA of ALTERA is divided into commercial grade and industrial grade. The junction temperature range for normal operation of commercial grade chips is 0~85 c, while that of industrial grade chips is -40~100 c.In practical circuits, we must ensure that the junction temperature of the chip is within the tolerable range.

As the power consumption of the chip increases, more and more heat will be generated during operation.If the junction temperature of the chip is to be maintained within the normal range, certain methods must be adopted to make the heat generated by the chip rapidly disperse into the environment.

Had learned the person of middle school physics to know, heat transfer basically USES 3 kinds of methods, namely conduction, convection and radiate, chip is to use these kinds of means to heat radiate outwards likewise.

The following figure shows a simplified model of chip cooling.Heat generated by the chip in the figure is mainly transmitted to the outer package of the chip. If there is no attached heat sink, it will be directly distributed to the environment by the chip package shell.If a heat sink is added, the heat will be transferred from the outer package of the chip to the heat sink through the heat sink adhesive, and then from the heat sink to the environment.Generally speaking, the surface area of the fin is quite large, and the contact surface with the air is large, which is conducive to heat transfer.In daily practice, it has been found that most of the heat sinks are black, because black objects tend to radiate heat outward, which is also conducive to heat emission outward.And the faster the wind speed on the fin surface, the better the heat dissipation.

In addition, a small amount of heat passes through the substrate of the chip to the solder ball of the chip, which then passes through the PCB to transfer the heat to the environment.Due to the small proportion of heat, this part is ignored in the following discussion of the thermal resistance of chip packaging and heat sink.

First of all, it is necessary to understand the concept of "thermal resistance", which describes the ability of an object to conduct heat. The smaller the thermal resistance is, the better the thermal conductivity is, and vice versa, which is similar to the concept of resistance.

From the silicon chip of the chip to the thermal resistance of the environment, assuming that all the heat is eventually distributed to the environment by the heat sink, a simple thermal resistance model can be obtained, as shown in the figure below:

Chip cooling model with heat sink

The total thermal resistance from the silicon wafer to the environment is called JA, so it satisfies the following requirements:

JA = JC + CS + SA

JC refers to the thermal resistance of the chip to the outer package, which is generally provided by the chip supplier.CS refers to the thermal resistance of the outer package of the chip to the heat sink. If the heat sink is attached to the chip surface with heat conducting adhesive, the thermal resistance is the thermal resistance of the hot glue, which is generally provided by the heat conducting adhesive supplier.SA refers to the thermal resistance of the heat sink to the environment, which is generally given by the heat sink manufacturer. The thermal resistance decreases with the increase of wind speed, and the manufacturer usually gives the thermal resistance under different wind speeds.

Chip packaging itself is as a cooling device.If there is no heat sink in the chip, JA refers to the thermal resistance value of the silicon chip after external packaging, which is obviously higher than the JA value of the heat sink.This value depends on the characteristics of the chip itself and is typically supplied by the chip manufacturer.

The graphic below shows the package thermal resistance of ALTERA's STRATIX IV devices.JA values of chips under various wind speeds are given, and these values can be used to calculate the situation without radiators.In addition, JC is used to calculate the total JA value with heat sink.

StraTIx iv device packages heat resistance

Assuming that the power consumed by the silicon wafer is P, then:

TJ (junction temperature) =TA+P*JA

It is necessary to satisfy that TJ cannot exceed the maximum allowable junction temperature of the chip, and then the maximum allowable requirement for JA can be calculated according to the ambient temperature and the actual power consumed by the chip.

JAMax= (tjmax-ta) /P TA (ambient temperature)

If the JA value of the chip package itself is greater than this value, it must be considered to add appropriate cooling devices to the chip to reduce the effective JA value of the chip to the environment and prevent the chip from overheating.

In the actual system, part of the heat will also be released from the PCB, if the PCB layer number, larger area, is also very conducive to heat dissipation.

Follow Me

Link:Tenco

twitter:https://twitter.com/TencoTechnology

facebook:https://www.facebook.com/tencotechnology

linkedin:https://www.linkedin.com/in/nicole-song-64400b147/

New bionic hand delivers position and haptic signals in real time

Researchers in Switzerland, Italy and Germany have recently developed a new type of bionic hand that can transmit position and tactile signals in real time, allowing patients to instantly and accurately sense the position of the limb during and after exercise, thereby improving the perception of the body.

The currently used myoelectric prosthesis allows the amputated patient to regain the autonomous motion control of the prosthetic limb using the residual muscle function of the forearm, but still lacks sensory feedback. This means that patients must rely heavily on visual cues and cannot feel that the prosthesis is part of their body and is unnatural to use.

Researchers at the Federal Institute of Technology in Lausanne, Switzerland, the Institute of Advanced Studies in Santa Ana, Italy, and the University of Freiburg in Germany, after 10 years of robotic research, have developed new bionic hands that enable amputated patients to return to the subtle touch of nature.

The researchers implanted electrodes at the stump of the amputated patient to send electrical impulses and re-establish external information flow through internal stimuli. After receiving training, the patient gradually learned how to convert these pulses into proprioception and tactile sensations.

The new device allows the patient to extend the bionic hand to feel the shape, position, size and other information of the object without having to use the eye to view it. At present, this technique has successfully achieved high proprioceptive acuity in two amputated patients, and the success rate of two patients using prostheses to determine the size and shape of four objects has reached 75.5%.

According to the researchers, this sensory replacement device based on intra-neural stimulation provides position feedback and tactile feedback to the patient in real time, and the brain can fully synthesize this information. The patient's ability to process both feedbacks in real time after training is excellent, almost as much as using a real hand.

Follow Me

Link:Tenco

twitter:https://twitter.com/TencoTechnology

facebook:https://www.facebook.com/tencotechnology

linkedin:https://www.linkedin.com/in/nicole-song-64400b147/

France develops' robot ants' that can navigate by sunlight

Inspired by the Sahara desert ant, French researchers have developed a robot ant that can find its way without using global positioning system (GPS) and only USES sunlight to find its way home.This provides a new way of navigation for autonomous vehicles and robots.

The robot ant is a small, six-legged robot that can zigzag-walk 14 meters before returning to its starting point, with a margin of error of about 1 centimeter, researchers from the university of marseille and the national center for scientific research, among others, report in the new issue of the American journal science robotics.

Most insects rely on secreting pheromones for navigation, but the Sahara desert heat can instantly dry out the pheromone. The ants have thus evolved a special navigational ability: they use polarized light from specific wavelengths of sunlight to determine their direction, record their steps, and then combine that with a calculation of the exact path back to their nest.

Stephane viollet, a French bioroboticist involved in the new study, explained that although the sun's polarized light is invisible to the human eye, you can imagine there are lines in the sky that are oriented according to the position of the sun.
The researchers were inspired to develop the robotic ant, which weighs just 2.3kg, with an "optical compass" and a "light movement sensor".The "optical compass" USES two photodiodes to convert ultraviolet polarized light from the sun into electrical signals.The "optical motion sensor" can determine the moving distance through the number of steps, the relative speed of the machine and the ground.By combining directions and distances, the robot ant can determine its current position relative to its starting point.

Because ultraviolet light penetrates clouds, the robot ants can pinpoint their location on clear or cloudy days.In addition, the six-legged robot ant is highly mobile and can operate in complex environments where wheeled robots and drones cannot work.
The researchers said that autonomous driving using GPS positioning in urban environments could be subject to errors due to magnetic field interference, and that the positioning technology used by robot ants is a powerful complement to GPS, and that it will be necessary to explore how to use the technology at night and over longer distances in the future.

Follow Me

Link:Tenco

twitter:https://twitter.com/TencoTechnology

facebook:https://www.facebook.com/tencotechnology

linkedin:https://www.linkedin.com/in/nicole-song-64400b147/

How far is the hydrogen fuel cell car from us?

The University of Science and Technology of China announced that it has developed a new type of catalyst that can eliminate the "toxic shock" crisis of hydrogen fuel cell carbon monoxide, extend battery life, and widen the temperature limit of battery use to ensure that it can start normally in the cold winter.

Hydrogen fuel cells currently have many breakthrough innovations and patents, and have the advantages of less air pollution and relatively mature technology, but the high cost has constrained its development process. Xu Haidong, assistant secretary-general of the China Automobile Association, said: "Once the cost problem is effectively solved, the future hydrogen fuel cell technology will become an important support for the development of the new energy automobile industry. ”

In the field of hydrogen energy applications, automobile giants such as Japan and South Korea have been involved earlier. In February 2013, the world's first production version of the hydrogen fuel cell vehicle Hyundai ix35 FCV officially went offline, and now NEXO is also ready to go; Honda Clarity, Toyota Mirai and other concept cars have also been mass-produced. In the future, South Korea plans to increase the annual production capacity of hydrogen fuel cell passenger cars to 100,000 by 2025; Japan predicts that the global fuel cell market will grow 28 times in 2017 compared with 2017.

Compared with pure electric vehicles, hydrogen fuel cell vehicles have the characteristics of “short hydrogen charging time and long lasting life”. It is understood that the Honda Clarity concept car can be filled with hydrogen fuel in just 3 minutes, and can achieve a maximum cruising range of 750 kilometers. Therefore, the hydrogen energy vehicle industry is attracting more and more car companies. In June last year, Hyundai and Audi signed a contract to jointly develop hydrogen energy technology and hope to develop the hydrogen energy automobile industry chain. In addition, GM has established cooperation with Honda, BMW and Toyota.

Focusing on the domestic market, China has long established a hydrogen energy fuel cell research and development institution with the university research institute as the main body, and laid a certain foundation for automotive applications. In the passenger vehicle field, SAIC launched the Roewe 950 plug-in hybrid fuel vehicle. Great Wall Motor also acquired a 51% stake in Shanghai Fuel Cell Vehicle Power Systems Co., Ltd. and plans to launch the first hydrogen fuel cell vehicle in 2022. In the field of commercial vehicles, Yutong and Futian hydrogen fuel cell buses have been put into practical use, and China National Heavy Duty Truck has also developed three hydrogen energy fuel vehicles.

At present, the state has given strong support to the hydrogen energy fuel vehicles at the policy level. In February 2018, the Ministry of Finance, the Ministry of Industry and Information Technology, the Ministry of Science and Technology, and the Ministry of Development and Reform Commission jointly issued the "Notice on Adjusting and Improving the Financial Subsidy Policy for the Promotion and Application of New Energy Vehicles", stipulating that the fuel cell vehicle subsidy standard remains unchanged, while the local bicycle subsidy is not More than 100% of the national bicycle subsidy.

In the long run, “With the mass production of fuel cell auxiliary systems, the realization of key components including air compressors and humidifiers, the cost of fuel cell systems can be greatly reduced, and the cost of hydrogen fuel cell vehicles will be reduced to the traditional Car level." The person in charge of the car company said.

However, the development of hydrogen energy vehicles still faces many problems, such as the difficulty of hydrogen energy storage and the difficulty in building hydrogen refueling stations. According to the data, as of the end of 2017, there are 328 hydrogen refueling stations in operation worldwide, including 12 in China. However, these hydrogen refueling stations mainly provide replenishment services for R&D and demonstration vehicles and cannot be effectively popularized.

In response to the above problems, China proposed in 2018 that it should systematically promote the industrialization of fuel cell vehicles and accelerate the development of on-board hydrogen storage system technology. By 2020, the mass production and scale demonstration of fuel cell vehicles will be realized. According to industry insiders, hydrogen energy application is an important development direction and will change the existing energy landscape in the future. Ouyang Minggao, an academician of the Chinese Academy of Sciences and executive vice president of the China Electric Vehicles 100, even gave a specific time node. "In 2025, fuel cell technology will mature, and the cumulative promotion of automobiles will reach 50,000 to 100,000."

At that time, with the improvement of infrastructure and the continuous improvement of technology, hydrogen fuel cell vehicles with high efficiency, low pollution and long battery life will develop rapidly and eventually become an indispensable part of the new energy automobile industry.

Follow Me

Link:Tenco

twitter:https://twitter.com/TencoTechnology

facebook:https://www.facebook.com/tencotechnology

linkedin:https://www.linkedin.com/in/nicole-song-64400b147/

Samsung launches foldable phone

At the event in San Francisco, samsung electronics co., LTD., unveiled the first foldable smartphone of its kind, dubbed the Galaxy Fold, for $1,980.From the outside, the Galaxy Fold achieves one of the industry's long-held goals of being Able to bend.

The phone has a snapdragon 855 processor with a collapsed screen, 12GB of ram, 512TB of storage, 4380mAh battery and lateral fingerprint recognition.A version that supports 5G networks will also be released later. The phone will go on sale worldwide on April 26.

Samsung "false start" folding screen

DJ Koh, head of samsung's mobile business, said at the launch that the Galaxy Fold can prove to critics that the smartphone industry is Mired in innovation and market saturation that they are wrong. The phone has six cameras, the ability to run three apps at Once, a 7.3-inch diagonal screen when opened, and a second external display.

Follow Me

Link:Tenco

twitter:https://twitter.com/TencoTechnology

facebook:https://www.facebook.com/tencotechnology

linkedin:https://www.linkedin.com/in/nicole-song-64400b147/

Karl Lagerfeld, chanel designer, Is Dead

Karl Lagerfeld is one of the most prolific designers of the past half century. On February 19, 2019, Chanel announced that a generation of fashion designer Karl Lagerfeld died in Paris. The media said that he was 85 years old - he was vague about his age.

At the age of 14, Karl Lagerfeld of the metropolis left his hometown of Hamburg, Germany, to the fashion capital of Paris, and entered the fashion world through self-study. Since then, Karl Lagerfeld has been fascinated with the fashion industry for a lifetime, and has designed countless exquisite works for brands such as Fendi, Chloé and Chanel. He himself has also become a fashion logo - wearing a narrow version of men's clothing, wearing sunglasses, white ponytails, forever.

Carl Lagerfeld's most praised achievement is to bring Chanel, who was on the verge of bankruptcy, back to life.

In the 1970s, like other luxury brands, Chanel was obsessed with the rules after the death of the founder Coco Chanel. At the time, Chanel focused on the production of perfumes, and earned most of the profits, but ignored the innovation of Haute Couture, continued to retain or gently modify the design of the late founder, and gradually slipped to the edge of the fashion industry.

Nearly a decade after the founder passed away, the troubled Chanel boss Alan Wertheimer made an important personnel decision to hire Carl Lagerfeld, who had worked for another fashion brand Fendi, as Chanel designer. Plastic brand.

The fashion industry is changing rapidly. Popular today, it may change soon.
After Karl Lagerfeld's death, Chanel has announced that Karl Lagerfeld's longtime collaborator Virginie Viard will succeed Karl Lagerfeld's creative work.

Follow Me

Link:Tenco

twitter:https://twitter.com/TencoTechnology

facebook:https://www.facebook.com/tencotechnology

linkedin:https://www.linkedin.com/in/nicole-song-64400b147/

Chinese Lantern Festival why prosperous, why decline?

Today is the Lantern Festival, a traditional Chinese festival.Historically, it was the biggest carnival for Chinese people.

But today, compared with the Mid-Autumn festival and the Dragon Boat Festival, the Lantern Festival has received little attention.

The ancient people attached importance to the Lantern Festival, the main reason is that during the Lantern Festival, the imperial court will lift the curfew, allowing people to go out at night to celebrate. In normal times, people living in cities, except for funeral , medical treatment and marriage, are strictly prohibited to travel at night without any reason, or they will be flogged.During the Lantern Festival, people can break through the boundaries of high and low, go to the street to watch lanterns and guess riddles, And play freely.Weekday the woman in the home that be trapped, also had god-given opportunity to go out.

After the republic of China, the status of the Lantern Festival began to decline sharply.Because, after entering the republic of China, except in special circumstances, there is no curfew. The night life rights of the ancients were greatly suppressed by the curfew, So the Lantern Festival became a rare opportunity for "legal carnival".Curfews aside, the Lantern Festival "night tour" of the precious, nature will no longer exist.In addition, the society is becoming more and more open, men and women have Plenty of opportunities to communicate, also do not have to wait for the Lantern Festival.

How much modern people pay attention to a festival, largely depends on whether there is a holiday and holiday length.With a holiday, the Lantern Festival's presence would be diminished.

Lantern Festival, has become the Chinese people's biggest carnival, the Spring Festival "aftereffect".

Follow Me

Link:Tenco

twitter:https://twitter.com/TencoTechnology

facebook:https://www.facebook.com/tencotechnology

linkedin:https://www.linkedin.com/in/nicole-song-64400b147/

Scientists have invented a new thermal generator that can charge smart wearable devices

According to reports, scientists have developed a non-invasive wearable device that can extract electricity from body heat. The base of the device is non-toxic and non-allergenic, made of ordinary old cotton fabric.

On this cotton fabric wristband, a special coating is applied to collect the body temperature "power generation". Theoretically, one end of the fabric contacts the human skin, and the other end is exposed to the air, and the temperature difference between the two ends is greater. The electric output is larger.

Researcher Trisha Andrew, associate professor of chemistry at the University of Massachusetts at Amherst, said: "Coating is an important part of the technology." The research team used to use other ingredients to make energy harvesting devices of the same principle, but unfortunately toxic.

At the same time, human sweat can improve conductivity. This technology is suitable as a stable trickle charger for batteries, which in turn powers a wearable device, such as fitness trackers and medical monitors, especially for the current popular sports. Exercise to create a wearable device, this technology may solve its charging problem.

The research was published in the journal Advanced Materials Technologies, and the research team said it has patented the technology and is currently considering using it for future charging of wearable products.

Follow Me

Link:Tenco

twitter:https://twitter.com/TencoTechnology

facebook:https://www.facebook.com/tencotechnology

linkedin:https://www.linkedin.com/in/nicole-song-64400b147/

History's first "robot citizen" Sophia has welcomed a little sister

Sophia the robot is known around the world for her jokes and was granted citizenship by Saudi Arabia for the first time in human history.Sophia has almost exactly human skin: made with a malleable material called Frubber, the pores of her face can be anywhere from 4 to 40 nanometers in size, and her face and neck have 62 muscle structures that allow for natural facial expression.

Sophia recently welcomed a "" little sister" "Sophia, a new STEM, AI and programming robot aimed at kids ages 7 to 13.
At present, little Sophia is crowdfunding on the foreign crowdfunding website Kickstarter, with the goal of 75,000 dollars, which has reached 126,000 dollars, and there are still 47 days left for crowdfunding, and the expected delivery date is December 2019.

According to the official introduction, little Sophia has the same lovely personality as Sophia, is playful and curious, can generate a variety of human facial expressions, and can respond to orders, positive dialogue.

Little Sophia is the first consumer robot independently developed by Hanson Robotics.

Follow Me

Link:Tenco

twitter:https://twitter.com/TencoTechnology

facebook:https://www.facebook.com/tencotechnology

linkedin:https://www.linkedin.com/in/nicole-song-64400b147/

Ai wins starcraft and then has to challenge tower building

For decades, various artificial intelligences have gradually won competition with humans in competitive games, such as chess, go, even Rubik's Cube, StarCraft, and so on. Nowadays, robots have begun a new exploration - the stacking game.

A recent video from the Massachusetts Institute of Technology shows that a robot developed by the school's engineers is playing the game with amazing precision. Alberto Rodriguez, Department of Mechanical Engineering at the Massachusetts Institute of Technology, said: "This robot is equipped with a soft gripper, a force wristband and an external camera that can make the robot look like a human. The weakness of the perceived tower."

"Unlike purely cognitive games such as chess and go, stacking games require players to master physical skills such as detecting, pushing, pulling, placing, and building blocks. It requires interactive sensing and operation. You must touch the wood. The tower learns how to move bricks and master the timing of moving bricks. It's hard to simulate, so robots must learn in real life and interact with real stacks, Rodriguez said.

Researchers say the robot shows that machines can learn how to perform certain tasks through tactile and physical interactions rather than relying solely on the visual system. This sensitivity is important because it further demonstrates that robots can be used to perform tasks that require subtle operations or are extremely flexible.

Rodriguez said: "In the assembly line of mobile phone production, almost every step of buttoning or screwing feels from the feedback of force rather than vision. Using this behavior as a learning model is to build this technology. Important foundation."

To be a skilled gamer, robots don't need a lot of imaginary exercises. The researchers designed 300 small games for robots to train in. At present, robots have begun to confront humans. Of course, robots are not humans. The opponent, the future is hard to say.

Follow Me

Link:Tenco

twitter:https://twitter.com/TencoTechnology

facebook:https://www.facebook.com/tencotechnology

linkedin:https://www.linkedin.com/in/nicole-song-64400b147/

The first quantum computer power source in Russia has been developed

Quantum computers cannot use ordinary power supplies because such computers may treat small changes in current performance as changes in the processed information and give erroneous results. Russia's Novosibirsk State Technical University developed the first quantum computer power supply in Russia and tested it.

To date, expensive imported power sources have been used for research related to the manufacture of Russian quantum computers. According to Alexei Vostrezov, the academic vice president of the National Technical University of Novosibirsk, the multi-channel power supply successfully produced by Russian engineers is as good as similar foreign products.

Vostrezov believes that from the perspective of national security, the manufacture of domestic quantum computer power is of great significance. In recent years, the competition of quantum technology has mainly been carried out among major powers. At present, China, the United States and Russia are actively developing quantum computers with multiple qubits. In the fall of 2018, the EU launched a 1 billion euro quantum technology development plan. The first country to create a quantum processing information system will gain significant advantages over other countries. The amount of computation that quantum computers can do in minutes or even seconds, and modern computers take years.

Follow Me

Link:Tenco

twitter:https://twitter.com/TencoTechnology

facebook:https://www.facebook.com/tencotechnology

linkedin:https://www.linkedin.com/in/nicole-song-64400b147/

Beidou satellite "escort" Western Pacific real-time scientific observation network data transmission

On the 31st, China's new generation of ocean-going comprehensive scientific research ship "Science" successfully completed the Western Pacific comprehensive inspection voyage and returned to Qingdao's home port. The expedition team carried out maintenance and upgrade of the West Pacific real-time scientific observation network in this voyage, realizing the real-time transmission from Beidou satellite. Observing network data improves the security, autonomy and reliability of real-time transmission of deep sea data.

Wang Jianing, the chief scientist of the voyage and a researcher at the Institute of Oceanology of the Chinese Academy of Sciences, said that the expedition team carried out maintenance and upgrades on the 20 sets of potential targets of the Western Pacific Real-Time Scientific Observing Network, including replacing batteries, optimizing stations and installing Beidou satellite communication modules.

Since the Beidou satellite is generally used in ships and island reefs, the communication module size and power consumption are not limited. The submarine standard volume is very small and can only be powered by batteries. This requires that the Beidou satellite communication module not only has to be small, saves electricity, but also runs stably. To this end, the Institute of Oceanology of the Chinese Academy of Sciences has specially developed the Beidou communication module suitable for the submarine.

“In addition, data such as seawater temperature, salinity, flow rate and flow direction observed by submarine targets are transmitted back to the land laboratory through satellite every hour, and the amount of data is large. To this end, we have developed a multi-module communication transmission technology.” Wang Jianing Said, "It's like transferring a movie. We split it into 10 copies and transfer it to a computer at the same time with 10 mobile phones. The transmission efficiency is greatly improved. After receiving different data packets, the background is combined into one. the film."

It is understood that since the use of Beidou satellite, the real-time data transmission of the Western Pacific Real-Time Scientific Observation Network is very stable.

Wang Fan, director of the Institute of Oceanology of the Chinese Academy of Sciences, said that the Western Pacific Real-Time Scientific Observation Network realized the use of Beidou satellite to transmit real-time observation data, which changed the history of relying on foreign satellites in the past and improved the security, autonomy and reliability of real-time transmission of deep-sea data. .

This voyage, the expedition team members inductive coupling and underwater acoustic communication technology, the depth of real-time transmission of observation data from 3,000 meters to 6000 meters.

It is understood that China's self-constructed Western Pacific real-time scientific observation network currently has 20 sets of submersible standards, 4 sets of large buoys and shipborne mobile observation equipment, etc., and has continuously obtained 5 years of deep sea observation data in this area.

Wang Fan said that the data obtained by the Western Pacific Real-Time Scientific Observatory will serve deep-sea frontier research, climate prediction and marine environmental forecasting, especially the data transmitted in real time will improve the accuracy of climate and marine environment prediction.

Follow Me

Link:Tenco

twitter:https://twitter.com/TencoTechnology

facebook:https://www.facebook.com/tencotechnology

linkedin:https://www.linkedin.com/in/nicole-song-64400b147/