“Mounting ESD protection elements such as multilayer chip varistors and Zener diodes near the source of ESD can effectively deal with ESD. However, the intrusion path of ESD is difficult to determine, which often leads to the situation that the installed ESD protection element does not exert its original strength. In order to exert the original strength of the component, we must determine the intrusion path of ESD, and it needs to be installed near the source of ESD. That’s why we’ve investigated the importance of mounting locations using an ESD visualization system, which we’ll walk you through in this tweet.
Mounting ESD protection elements such as multilayer chip varistors and Zener diodes near the source of ESD can effectively deal with ESD. However, the intrusion path of ESD is difficult to determine, which often leads to the situation that the installed ESD protection element does not exert its original strength. In order to exert the original strength of the component, we must determine the intrusion path of ESD, and it needs to be installed near the source of ESD. That’s why we’ve investigated the importance of mounting locations using an ESD visualization system, which we’ll walk you through in this tweet.
ESD Visualizer – Optimized Substrate Layout
An ESD visualization device is a device that visualizes ESD current by automatically scanning ESD current with a non-contact magnetic field probe. Because the electric field intensity distribution in the scanning area can be obtained, it is an effective tool for optimizing the substrate layout in ESD protection countermeasures. With this device, it is possible to observe the movement of ESD on the substrate depending on the mounting position of the ESD protection element.
Figure 1 ESD visualization equipment
ESD response depending on mounting position (Multilayer Chip Varistor)
ESD response was evaluated using the following substrates. The protection target products use LEDs, and the ESD protection elements use multilayer chip varistors. Install chip varistors at about 10mm and about 40mm from the pivot point (★) in the figure below, and observe the movement of each ESD.
Figure 2 Evaluation substrate and verification conditions
ESD trends when chip varistors are mounted at about 10mm (left) and about 40mm (right). The closer the chip varistor is placed, the more ESD flows to the varistor and the less ESD flows to the LED line.
The ESD reaction is as follows:
① Installation position 10mm
② Installation position 40mm
It can be seen that when the installation position of the chip varistor is about 10mm away from the fulcrum, ESD will flow into the installation line of the varistor immediately after entering the circuit. Even at the peak time of ESD, it can be seen that it mainly flows to the chip. Varistor installation wiring.
Figure 3 Time delay before and after ESD application (installation position: 10mm)
On the other hand, when the mounting position of the chip varistor is about 40mm away from the fulcrum, ESD flows into the LED line immediately after entering the circuit, and also flows into the LED line at the peak. This means that a relatively high electrical load is applied to the LEDs.
Figure 4 Time delay before and after ESD application (installation position: 40mm)
Optimum Mounting Configuration of Chip Varistors in ESD Countermeasures
Field strength analysis of the mounting location of the chip varistor shows that ESD is introduced about 0.3ns faster at 10mm (blue). This 0.3ns time is a very significant difference for an ESD with a peak time of about 1ns. In addition, the electric field strength at the peak is higher because the ESD can be introduced earlier. This means that more ESD can be introduced onto the chip varistor if the chip varistor is mounted close to the source of ESD entry.
Figure 5 Electric field strength
Under the above verification conditions, the ESD withstand Voltage was actually measured, and it was found that the ESD withstand voltage was higher when the ESD protection components were installed and the installation position was closer to the ESD entry source. This means that in order to take better ESD countermeasures, it is most appropriate to mount the chip varistor close to the source of ESD entry.
Figure 6 ESD withstand voltage
TDK’s Chip Varistors for Optimal ESD Countermeasures and Optimal Substrate Layout
With the complexity of substrates, even if the source of ESD intrusion can be identified, it can be limited by the nearby installation space. One of the features of TDK’s multilayer chip varistors is the inclusion of a miniaturized product lineup. The chip varistor we are currently mass-producing has a minimum size of EIA01005 (0.4 x 0.2 mm) for consumer products, and the industry’s smallest EIA0402 (1.0 x 0.5 mm) for automotive. Therefore, if TDK chip varistors are used, space can be saved, and installation and deployment with a high degree of freedom can be realized.
Figure 7 Features of TDK’s special chip varistors: miniaturization
With the advent of the 5G era, various new technology patents continue to emerge. While focusing on technology research and development, we should also focus on intellectual property protection. Recently, two former ZTE engineers were sentenced for allegedly infringing on trade secrets. This is also the first domestic intellectual property infringement case involving 5G technology.
According to Nanfang Daily, two former engineers, Huang Mouyu and Wang Mou, were both sentenced to three years in prison, suspended for four years, and fined 150,000 yuan for allegedly infringing on trade secrets. The two defendants pleaded guilty and did not appeal.
Among them, Huang Mouyu worked in ZTE Corporation from 2002 to January 2017, and held positions such as RF engineer and wireless architect; Wang Mou worked in ZTE Corporation Xi’an from April 2008 to October 2016 Research Institute, served as RRU department R&D engineer and other positions.
The case can be traced back to 6 years ago. It is reported that Huang Mouyu accepted the technology outsourcing project of a research institute’s 5G active antenna prototype in 2014, and signed 4 contracts with the above-mentioned research institute, the contract amount is as high as 2.35 million Yuan. Wang was responsible for the technical implementation of the project. After the research and development was completed, a 5G active antenna prototype and related technical documents were delivered to the research institute in stages. The identification showed that the technical documents delivered by Wang were identical with those of ZTE Corporation, and belonged to the technical information strictly confidential of ZTE Corporation. The estimated value of these information was RMB 4.3 million.
In June 2019, the Shenzhen Nanshan District Procuratorate brought a public prosecution to the court against Huang Mouyu and Wang Mou for allegedly infringing on trade secrets. In December of the same year, the Nanshan District Court of Shenzhen sentenced the defendants Huang Mouyu and Wang Mou to the crime of infringing trade secrets, and both were sentenced to three years in prison, four years of probation, and a fine of RMB 150,000. The two defendants pleaded guilty and did not appeal.
Within the law, human feelings depend on. According to the procuratorate’s understanding and ZTE’s feedback, Huang Mouyu made a great contribution to the company during his work, and he did not use ZTE’s technology after leaving to start a business. As long as Huang Mouyu pleads guilty and repents and compensates for the loss, the company is willing to forgive him. After coordinating with ZTE Corporation, Huang Mouyu and Wang Mou pleaded guilty and repented and compensated ZTE for the loss, and obtained the company’s understanding.
In the 5G era, ZTE actively develops its layout
As we all know, 2019 is also known as the first year of 5G in my country. ZTE, as a well-known communication manufacturer in China, is actively planning for 5G business.
(Data sourced from ZTE’s 2019 Annual Report)
In the 2019 annual report released by ZTE, ZTE achieved an operating income of 90.737 billion yuan in 2019, a year-on-year increase of 6.11% to 85.513 billion yuan in 2018; net profit was 7.552 billion yuan, a year-on-year increase of 6.11%. The loss in 2018 was 612 million yuan, an increase of 1134.02%.
The reason for such a large loss in 2018 is well known to everyone. In the “Announcement on the Progress of Major Events and Resumption of Trading” issued by ZTE on June 12, 2019, it was also mentioned that the loss was mainly due to the US embargo. Operating losses and accrued losses caused by the blocking incident, as well as the subsequent $1 billion fine.
(Data sourced from ZTE’s 2019 Annual Report)
According to ZTE’s announcement, the company is committed to providing customers with satisfactory ICT products and solutions. The products are mainly related to the communication equipment manufacturing industry, focusing on the three major business areas of “operator network, government and enterprise business, and consumer business”.
In terms of operator network, ZTE’s 5G RAN, core network, transmission and other products have fully entered the leader quadrant, and its competitiveness has been further enhanced. In the field of wireless products, ZTE has also stepped into the first camp of 5G industrialization, continued to innovate in 5G technology and applications, and cooperated with more than 70 operators and more than 300 industry customers around the world in 5G business. 7nm 5G chips have been realized. Commercial. In the field of wired products, self-developed core dedicated chips with high integration, high performance and low power consumption were launched to enhance the competitiveness of wired products. The cumulative shipments of PON, FTTx, and 100G optical transmission networks ranked second in the world; video and energy In the product field, based on the company’s original technical foundations such as video encoding and decoding, access, transmission, and storage, a full range of products including video conferencing, video IoT, and cloud computing have become new growth points for operators’ network services in the 5G era.
In terms of government and corporate affairs, it focuses on the four traditional markets of energy, transportation, government affairs and finance. In June 2019, the “Double Hundred Thousand Plan” was released to provide customized industry solutions for 100 cities, 1000 districts, and 100 top 1000 enterprises to help customers achieve digital transformation. The company’s self-developed core products such as servers, videoconferencing, data communication, databases, and operating systems have also been widely used. The distributed database has been officially launched in the core business of large banks, and the application field of self-developed operating systems has continued to expand.
In terms of consumer business, it involves mobile phones, data cards, in-vehicle terminals, home information terminals, and fixed-line broadband terminals. Among them, there is no doubt about the development of 5G mobile phones in China. ZTE has long-term and in-depth cooperative relations with upstream device manufacturers and downstream operators in the industry chain, and has maintained a global leading position in the industry for a long time.
In terms of domestic and foreign markets, adhere to a positive and stable business strategy and expand new growth space. In addition to doing well in the construction of the original 4G-related business, at the same time grasp the 5G opportunity time window, firmly increase market share, continue to expand revenue, and continuously increase customers satisfaction.
It is not difficult to see from ZTE’s annual report that the keyword “5G” has covered all aspects of the company’s business. As the core strategy of ZTE’s development, 5G has continued to invest and innovate for many years. It already has a complete 5G end-to-end. The capability of the solution has been fully prepared for commercial use in wireless, core network, bearer, chip, terminal and industry applications.
The first quarter financial report reflects the impact of the epidemic
The rapid development of the domestic 5G industry in 2019 makes people also optimistic about 2020, but the unexpected outbreak of new coronary pneumonia has brought the originally popular 5G industry to a freezing point: equipment manufacturing plants are shut down, offline stores are closed, and the new coronary pneumonia epidemic has brought the communication industry to a standstill. The short-term impact is also starting to show up in earnings reports.
(Data sourced from ZTE’s 2019 Annual Report)
On the evening of April 24, ZTE released its financial report for the first quarter of 2020. The financial report shows that the company achieved operating income of 21.484 billion yuan during the first quarter of the reporting period (January-March 2020), a year-on-year decrease of 3.2%. %; net profit attributable to ordinary shareholders of the listed company after deducting non-recurring gains and losses was 160 million yuan, a year-on-year increase of 20.5%; net profit attributable to ordinary shareholders of the listed company was 780 million yuan, a year-on-year increase of 780 million yuan Down 9.6%.
According to the proportion of domestic and foreign business in ZTE’s 2019 annual report, the company’s business in China and outside China accounted for 64.16% and 35.84% respectively, and overseas business accounted for more than 1/3, which is not a small proportion. Judging from the current development of the global new crown pneumonia epidemic, there are more than 1.8 million confirmed cases outside China, and the cumulative number of confirmed cases exceeds 2.8 million. The spread of the epidemic is not optimistic. The severity of the overseas epidemic has also greatly affected the overseas business development of domestic manufacturers.
(The data comes from the Baidu epidemic real-time big data report)
ZTE Corporation stated in the announcement that in the face of the epidemic in the first quarter, ZTE Corporation prioritized protecting the health of its employees and ensuring normal services to global customers. Partners are actively fighting the epidemic, using digital platforms to help resume work and production in an orderly manner, and actively promoting business progress related to “new infrastructure”. The business remained stable in the first quarter.
With the rise of the new infrastructure wave, the protection of intellectual property rights of 5G technology is more important
This year, with the rise of the concept of “new infrastructure” in China, 5G has become one of the most important development areas under the wave of new infrastructure. my country attaches great importance to the construction of 5G infrastructure. As a new generation of mobile communication technology, 5G has technical characteristics such as higher speed, shorter delay and greater connection than 4G. It focuses on supporting enhanced mobile broadband, ultra-reliable and low-latency communication and massive Three types of application scenarios for machine communication.
With the accelerated commercialization of 5G, the global communications industry will usher in the development of the entire industrial chain of “chips, devices, networks, terminals, business and services”, and the importance of 5G technology is self-evident.
In terms of 5G patents, global manufacturers are competing for each other. According to a joint study by the Technical University of Berlin and the German Intellectual Property Research Corporation, Huawei is currently the company with the largest number of 5G patents in the world, with a total of 3,147 5G patents, followed by Samsung. Electronics, with a total of 2,795 5G patents, ranked third with ZTE with 2,561 5G patents. From this point of view, my country occupies 2 of the top three 5G patents.
As far as my country’s current 5G development is concerned, on the one hand, countries around the world are actively seizing the high ground for 5G construction and promoting the large-scale deployment of 5G commercial use; The suppression will adversely affect the internationalization of my country’s 5G products.
For ZTE, the intellectual property protection of 5G technology patents is not only a prerequisite for accumulating technology and developing business, but also affected by “learning from the past” to avoid the United States making a fuss about technology patents in the future; for my country, In order for 5G patented technology to be more transformed and applied, it is necessary to further strengthen the intellectual property protection of 5G patented technology, so as to have more voice and international influence in the future.
On September 12, 2020, the 2020 China (Shenzhen) International Automotive Electronics Industry Annual Conference and the 2019 Automotive Electronics Science and Technology Award Ceremony, which has attracted much attention from the industry, was grandly held at the Hyatt Regency Shenzhen. During the award ceremony, NavInfo’s Automotive Electronic chip design enterprise – AutoChips of Jiefa Technology, with the excellent performance of “AC8257 Internet of Vehicles SoC chip”, was reviewed by an independent expert group behind closed doors, and stood out among many selected products, and won the “Annual Outstanding Innovative Product Award” at this annual meeting. ” and “Annual Most Investment Value Award”.
Behind the award is the industry’s high recognition of Jiefa Technology’s AutoChips chip products. At the same time, it is also a powerful testimony of Jiefa Technology’s AutoChips’ continuous investment in the automotive electronics industry, concentrating on making good products and improving R&D strength.
Pictured are photos of the awards
The picture shows the award photo
About Jiefa Technology AC8257
AC8257 is an in-vehicle-specific high-integration and high-performance car-connected entertainment information system SoC that integrates 4G Modem and BT&WIFI&GPS basebands independently developed by Jiefa Technology. It adopts 14nm FinFET advanced technology and meets the operating temperature range of -40~+85℃. Built-in multi-core CPU, high-performance GPU, independent dual ISP, support high-definition 3D360 surround view AVM, 2S high-definition reversing image Display, multi-channel high-definition video recording at the same time, 3mA ultra-low power network standby, support remote car control and monitoring, AR panoramic navigation , DMS fatigue warning; while meeting the needs of rich in-vehicle multimedia infotainment, it enhances the collection and processing speed of IoV big data and communication transmission capabilities, and achieves technological innovation and breakthroughs in ultra-low power consumption design and independent algorithms. The high cost performance has also won the AC8257 a strong market competitiveness. At present, the AC8257 has been successfully mass-produced in the front-mounted models, achieving another major breakthrough in the field of car networking with domestic chips. This annual meeting conducted in-depth discussions on the domestic and foreign automotive electronics industry trends in 2019 and 2020. At the same time, it analyzed the new pattern of the automotive electronics industry from multiple levels and angles, including OEMs, Tire1, BAT, solution providers, and chip manufacturers. New changes, discussing the opportunities and challenges brought by intelligent networked vehicles to the industry, the conference also invited guests from OEMs of independent brands and joint venture brands (research institutes, planning institutes, technology centers, supply chain centers, R&D and procurement departments, etc. ) shared with the conference.
The picture shows the scene of the meeting
The picture shows the brand Display of Jiefa Technology. This annual meeting coincides with the tenth anniversary of the establishment of the organizer, Shenzhen Automotive Electronics Industry Association. The theme is “Embrace 5G, Innovative Development, Based on the Greater Bay Area, and Entering the New Decade”. Next, the representatives of participating companies and visiting guests are the highest in history. Nearly 40 major OEMs have gathered, including FAW, SAIC Motor, Changan, Geely, BAIC, GAC, Great Wall, Dongfeng, Chery, SAIC-Wuling, JAC , Shaanxi Automobile, Liuqi, Brilliance and other domestic self-owned brand car manufacturers have a strong lineup of guests, which also provides Jiefa Technology AutoChips with an excellent platform for communication with OEMs, technology docking, product introduction, and brand promotion. While sponsoring the seatback advertisement of the annual meeting, Jiefa Technology AutoChips brought the newly developed AC8015 (smart cockpit SoC), AC7801x (vehicle MCU), AC5111 (TPMS special chip) to the product display of the annual meeting, leaving a message for the guests. After a good impression, the AutoChips car gauge chip also received high attention from the guests present, and the atmosphere of on-site communication was lively.
The picture shows Jiefa Technology’s booth Jiefa Technology AutoChips, as an industry-leading enterprise focusing on automotive electronic chip design for nearly ten years, in recent years, with the continuous deepening of the pre-installation business, with excellent product performance, automotive-grade quality, and long life Cycle guarantee and cost-effective solutions, AutoChips automotive-grade chip products have been fully affirmed by major mainstream car manufacturers and auto parts manufacturers, and their cooperative relations have become more and more close. With the increasing number of mass-produced models, Jiefa Technology AutoChips The market share of installations will surely achieve a leap-forward increase. In the future, AutoChips of Jiefa Technology will join hands with the vast number of partners, with the concept of “focus, quality and service”, to deeply cultivate the industry and create greater glories for China’s automotive electronics industry.The above content is reproduced from NavInfo’s new WeChat public account
Original title: AutoChips of Jiefa Technology debuted at the 2020 China (Shenzhen) International Automotive Electronics Industry Annual Conference AC8257 and won two awards
Article source:[WeChat public account: Shenzhen Automotive Electronics Industry Association]Welcome to add attention! Please indicate the source when reprinting the article.
Responsible editor: haq
There are positive signals in the folding screen mobile phone market. The first batch of folding screen mobile phones sold well, and the other giants are changing their pessimistic views
Recently, discussions about the release of Huawei’s new-generation foldable phone Mate X2 next month have increased, and Xiaomi’s patent for a MIX foldable phone has also been exposed.
The Korea Business Daily reported that Samsung may abandon the Galaxy Note series and devote itself to its folding screen mobile phone.
“Intelligent Objects” learned that the release date of Mate X2 is indeed approaching. This time, Huawei’s folding screen mobile phone has changed from the outer folding scheme adopted by the previous two generations, and adopted the inner folding design similar to Samsung, which greatly reduces the technical difficulty and cost. It is expected to be much larger than the previous two generations.
Behind Huawei’s first launch of a folding screen mobile phone is a series of ecological investment and innovation
The sales data of JD.com’s Samsung mobile phone store has changed. The Samsung Galaxy Z Fold2 series mobile phones released in August this year sold nearly 10,000 units on the platform, far exceeding the first-generation folding screen mobile phone released six months ago.
According to statistics, compared with the second quarter, the number of active devices for folding screen mobile phones in the third quarter of 2020 increased by 116%.
Information from reliable channels shows that, driven by the enthusiasm of the folding screen mobile phone market, the top five domestic mobile phone manufacturers, including Xiaomi, are already following up on folding screen mobile phones.
Huawei will release a new generation of folding screen mobile phones, Xiaomi and other major manufacturers are actively following up
Affected by immature technology and high cost, the future of folding screen mobile phones has huge uncertainties. Forbes once concluded in the article “Does Folding Screen Phones and Computers Have a Future?”, saying that folding screens will never become mainstream.
However, the enthusiasm of mobile phone manufacturers for folding screen mobile phones has not been dampened by external voices.
As a major player in the field of folding screen mobile phones, Huawei’s recent news all point to: it intends to increase shipments and promote the commercial progress of folding screen mobile phones.
“Intelligent Objects” learned that when the new generation of folding screen mobile phone Mate X2 is about to be released, Huawei also recently added orders for the previous generation folding screen mobile phone, about 50% of the order, which seems to respond to market demand.
Regarding the Mate X2, it is reported that the Kirin 9000 processor will enhance the performance of this phone. In addition, it will be equipped with 66W super fast charging, with a very narrow frame design and a full screen with a hole.
Unlike previous rumors, Huawei has done “subtraction” in terms of sales and folding methods that everyone cares about most. Or affected by the supply of chips, Huawei adjusted the sales plan of the new generation of folding screen mobile phone Mate X2, and still retained the sales volume of 1.5 million units, which is twice the previous increase. In terms of folding methods, Huawei said that it will give up the outer folding, and the Mate X2 will only adopt the more technically mature inner folding solution.
On the one hand, compared with the previous generation of mobile phones, the sales volume has increased significantly. On the other hand, instead of trying out the more technically difficult outer folding, it adopts the inner folding design to simplify the complexity, and instead piles up technologies in terms of performance and experience optimization. Existing product iterations to improve the coverage of mobile phones. It is not difficult to find that Huawei’s move should be intended to accelerate the commercialization of folding screen mobile phones.
Coincidentally, when Huawei is about to launch a new phone, Xiaomi’s first folding screen phone will also be available.
In 2019, Xiaomi once released a video of an engineering machine. Later, there were rumors that Xiaomi would launch a folding screen mobile phone, but no mass-production model was released. This year, Xiaomi has applied for a number of patents related to folding screens, including methods and devices for posture detection of folding screens, Electronic devices, and computer-readable storage media.
Zhiwu has learned that Xiaomi will launch its first folding screen phone in 2021.
It can be seen from the recent patent information that the Xiaomi folding screen mobile phone will adopt a relatively simple inward folding method, similar to Samsung’s Galaxy Fold. After folding, there will be an external auxiliary Display screen and a pop-up camera.
At present, as Royole, Lenovo, Xiaomi and other manufacturers have successively finalized, more and more players will enter the folding screen mobile phone market, and the industrial development will undoubtedly accelerate.
At the beginning of the year, CINNO Research predicted that global shipments of folding screen mobile phones will reach 2.9 million units this year, a year-on-year increase of 517%. The market is expected to grow tenfold in four years.
Apple rumors continue, but no conclusion
Although friends and businessmen are doing well, and forecasting agencies are mostly optimistic, Apple has never released information about folding screen mobile phones, which also casts a layer of uncertainty on the scale of commercial use of folding screen mobile phones.
Since 2017, the news of Apple’s folding screen phone has been active in the public eye.
And this year, with the increasing volume of Huawei and Samsung’s folding screen phones, Apple’s folding screen phones have also made the latest “progress”: In September this year, Apple was rumored to discuss samples of folding phone Display screens with Samsung, and in November The Verifier issued an article saying that Apple will launch two The folding screen mobile phone will be launched after the year, and now there is news that Apple’s folding screen mobile phone is undergoing 100,000 folding tests, and next year, Apple will launch a 1TB, folding version of the iPhone and has sent the prototype to Hon Hai, Japan Nippon… various The news suggests that Apple’s folding screen phone is coming.
In the past 5 years, Apple has missed a series of hardware innovations such as screen fingerprints and lifting cameras
However, judging from the fact that the adoption of the iPhone on the big screen and the advancement of 5G technology in the past were later than other manufacturers, Apple is more cautious than Android companies when it comes to blessing new technologies.
A previous article in Business Insider pointed out that Apple is unlikely to launch a foldable phone in the short term due to factors such as cost and product maturity.
In the early stage, affected by various factors such as the epidemic and technological maturity, the sales of Huawei and Samsung’s folding screen mobile phones have been bleak, and therefore the folding screen mobile phone market has always been tepid. So far, the folding screen mobile phone market has not been fully opened, and its sales have only accounted for 0.14% of the total sales in the past year, which is insignificant.
For Apple, it is difficult to have a huge appeal.
In fact, so far, the news that can be verified still stays in Apple’s patents in the field of folding screen mobile phones, and the current patent does not reveal the shape of Apple’s folding screen mobile phones, suggesting that it is still some time away from commercial use.
“Consumer car buying habits are changing, which is also driving the growth of the automotive electronics industry. Automakers are adding more new or enhanced Electronic components to passenger vehicles each year, with body electronics currently growing at four times the rate of vehicle production.
Consumer car buying habits are changing, which is also driving the growth of the automotive electronics industry. Automakers are adding more new or enhanced electronic components to passenger vehicles each year, with body electronics currently growing at four times the rate of vehicle production.
Some of the current trends in new or enhanced functions are the addition of more complex electronic components in order to improve brand reputation and competitive differentiation, while making consumers safer and more comfortable. For example a hybrid electric car is like putting an iPod? Connecting to car entertainment systems has now become a fashion. Consumers also see Bluetooth connectivity between cell phones and integrated speakerphone devices as standard.
These features are just the tip of the iceberg. Other well-designed complex features that are not seen or touched by passengers, but affect their driving experience, are gradually being introduced into car design. Sensing lighting systems, multi-axis adjustable seats, intelligent weather control systems, collision avoidance systems and power cruise control have become extremely important in the 21st century automotive market. Consumers even expect high-quality dashboard features from automakers. Bringing these advanced capabilities into automotive systems often comes at a price.
One of the challenges for automotive electronics designers is to rapidly introduce new electronic components that improve passenger comfort, safety protection and other enhancements. Designers must reduce overall design and certification time and enhance existing system functionality without compromising increasingly stringent quality and reliability requirements and cost goals. To overcome these challenges, automotive electronics designers need more integrated solutions to increase the functional density of the system. High-function integration of mixed-signal components is an attractive alternative.
Capture, compute and communicate
new design challenges
Fuel tank sensing is a good example of the challenges faced by automotive electronics designers. Only a few years ago, fuel level sensors were a fairly straightforward design issue. It consists of a simple float device with scanning carbon brushes contacting a resistive surface, which causes the analog output Voltage to be proportional to the amount of oil remaining in the tank. But with today’s cars, tank design typically has to wait until near the end of the platform design, and most likely uses any unused space. This can result in an oddly shaped tank and a capacity no longer proportional to the liquid level, which complicates the design of the pontoon system. More importantly, the advent of alternative fuels and fuel derivatives has made the fuel composition of the tank important. For example, the ratio of gasoline to ethanol fuel affects engine dynamics such as ignition, burn time and exhaust emissions. Manufacturers now believe that a new generation of fuel tank sensors must be able to determine fuel composition, while providing this information to the car’s other electronic control systems. This has turned what was once considered a simple sensing design into a complex analytical control challenge.
It is worth noting that almost all systems in the car are being expanded. Active dew-point controllers are replacing windshield defogging, which avoids or eliminates the conditions needed for water droplets to condense. The rain-sensing wiper system integrates motor control and rain-sensing functions into one system. The closing of next-generation anti-pinch windows and sunroofs is another representative application where the microelectronic components of these safety systems need to be integrated.
The first generation of anti-pinch technology
The first generation of anti-pinch designs typically consisted of a mechanical drive system powered by an electric motor. The motor current is monitored by a controller and then compared to a fixed threshold representing a stall condition (where the motor is blocked from turning); as soon as this threshold is reached, the direction of the window is reversed from up to down. This system is shown in Figure 1.
Figure 1: Control diagram of the first-generation anti-pinch window lift system
The first-generation design had several shortcomings. The first is to develop a method to distinguish the motor stall current when the motor is started and when the window is blocked (Figures 2 and 3). To meet this requirement, a fixed delay is added to the comparator circuit to ensure that it only starts comparing the stall current threshold after the motor has turned, although this sometimes fails to provide anti-pinch protection for a half-open window. For example, if the starting position of the window is only 10mm from the top, then the window is likely to hit the hard-stop before the critical timer expires.
Figure 2: Current Variation with Closed Window
Figure 3: Current Variation When Closing the Windows Meets Obstruction
The second disadvantage is that the parameters of the mechanical system can change over time, which can affect the working load of the motor, making the anti-pinch threshold larger or smaller.
Finally, these systems cannot adapt to changes in the driving environment due to the use of fixed thresholds. Thermal expansion effects of window weatherstrips can have a large effect on workload due to temperature changes. The force required to close the sunroof when the car is stationary is very different from that of a moving vehicle, and the force required to raise the window on a smooth road is also different from when the vehicle is driving on a rocky road. In both cases, the inability to compensate for these changes can affect safety or cause the windows to not operate properly.
Designers have tackled these three important challenges in different ways in the past. In some cases, they will add more sensors or use more precise control materials and components to alleviate these problems, but these approaches increase the cost and complexity of the design. This makes them increasingly need a low-cost anti-pinch function design to overcome these shortcomings.
new design solutions
As shown in Figure 4, a mixed-signal microcontroller containing a high-speed central processing unit (CPU) and a high-performance analog-to-digital converter (ie, bandwidth greater than 180 MSPS and resolution greater than 12 bits) is the best solution to this problem .
Figure 4: Anti-pinch system using a mixed-signal microcontroller
This approach allows designers to use a microcontroller to perform both the communication functions of the motor and the monitoring of the motor current. Communication noise can be detected directly by the on-chip analog-to-digital converter on the current sensor (ie, the shunt resistor) in the motor power circuit. This method can more accurately distinguish whether the motor is running or stalled, not only does the comparator circuit not need to add a fixed delay time, but also provides a complete anti-pinch function even when the window is half-open.
As shown in Figure 5, the system sets a variable motor current threshold based on historical data and parameter calculations to dynamically respond to motor load changes and limit system torque to an appropriate range, while limiting long-term factors such as motor wear and seals material aging) and short-term factors such as environment, humidity, temperature and vibration are taken into account. In addition, the system can exchange information with other electronic control units (ECUs), and use information such as outside temperature and vehicle speed as weighted inputs to determine appropriate thresholds (see Figure 6). Utilizing other systems not only improves overall system performance, but also avoids the additional cost of duplicating sensors on the vehicle.
Figure 5: Current variation during window closing with variable thresholds
Figure 6: Environmental parameters and historical data stored in in-memory tables that can be used to determine critical values
Automotive applications account for one-third of 8-bit microcontroller sales, and not only has the market size exceeded $3 billion, but it is also growing at a rate of nearly 10% per year. Automotive embedded system designers must develop more reliable, lower cost and more integrated solutions, so they need the most advanced microelectronic building blocks at their disposal. Mixed-signal microcontrollers with powerful analog and digital performance are the most cost-effective solution for these next-generation automotive electronics applications.