“Not long ago, the General Office of the State Council issued the “New Energy Vehicle Industry Development Plan (2021-2035)”, which clarified the encouragement and support for various fields of the new energy vehicle industry chain, showing a very positive signal: the development of domestic new energy vehicles since then. The direction will cover the whole industry chain, the whole scene and the diversification of energy. It can be said that new energy vehicles are not only the main direction for the transformation, upgrading and green development of the global auto industry, but also a strategic choice for the high-quality development of my country’s auto industry.
Not long ago, the General Office of the State Council issued the “New Energy Vehicle Industry Development Plan (2021-2035)”, which clarified the encouragement and support for various fields of the new energy vehicle industry chain, showing a very positive signal: the development of domestic new energy vehicles since then. The direction will cover the whole industry chain, the whole scene and the diversification of energy. It can be said that new energy vehicles are not only the main direction for the transformation, upgrading and green development of the global auto industry, but also a strategic choice for the high-quality development of my country’s auto industry.
Bloomberg predicts that sales of new energy vehicles will exceed sales of gasoline vehicles in 2038
Since the state subsidies began to decline sharply from last year, the new energy vehicle market has entered a more healthy and benign product and market-driven stage after the decline and consolidation from the second half of last year to the first half of this year. “Improving the core technology of new energy vehicles is a necessary condition for us to compete with the brands of developed countries.” Feng Yixin, director of the product management department of Fujitsu Electronic components (Shanghai) Co., Ltd., said at a recent event. How to strengthen the core technology of new energy vehicles? As the world’s leading manufacturer of high-performance non-volatile memory, Fujitsu semiconductor‘s ferroelectric random access memory products (hereinafter referred to as FRAM) are the first safety considerations for automotive applications. Since 2017, it has launched a variety of FRAM products have successfully entered the supply chain of many Tier-1 and Tier-2 OEMs by expanding the operating temperature range (minus 40°C to 125°C) and further improving product reliability.
Facing the pain points of new energy vehicle storage
In recent years, my country’s new energy vehicle industry has developed rapidly and has become an important growth point for the auto industry. According to the 2018 new energy vehicle sales statistics, 11 brands in the TOP20 are from China. The rapid growth in sales of new energy vehicles has naturally driven the development of the related automotive electronics industry chain. Due to the use of electric drive, the structure of new energy vehicles is different from traditional fuel vehicles, power batteries, battery management systems (BMS), and vehicle control units. The three major systems (VCU) have become the core functional components of the car, and the proportion of the cost of automotive electronics to the value of the entire vehicle has further increased.
Sales Statistics of New Energy Vehicles in 2018
“We believe that high-performance memory FRAM will be a key element to improve these core technologies. Whether it is BMS or VCU, these systems need to monitor, record and analyze current status information in real time and continuously.” Feng Yixin said, “Therefore , needs to improve memory performance and endurance design. Only non-volatile, high-speed, high-read and write-endurance automotive-grade memory FRAM can meet the required reliability and latency-free requirements.”
BMS and VCU are the core technologies of new energy vehicles
BMS is an important link between on-board power batteries and electric vehicles. Its main functions include: real-time monitoring of battery physical parameters; battery state estimation; online diagnosis and early warning; charge, discharge and pre-charge control; balance management and thermal management; and so on. “To give a simple example, the battery power is generally maintained between 30% and 75%, which means normal operation. If there is an imbalance, it needs to be supplemented from other units. At this time, the system needs to detect and record the power and temperature of the battery cells. , voltage, current and other data, and the time interval of a single monitoring and recording cannot be too long. This means that the data recording and writing of the BMS are also very frequent, and the number of times of writing to the non-volatile memory is relatively high. “Feng Yixin said.
Application of FRAM in Battery Management System BMS
At the same time, in actual work, the BMS system will not only record the current data such as the voltage, temperature and current of the battery cells at a frequency of every second or every 0.1 seconds, but also monitor the short-term (the last few charging cycles) and long-term (the entire charging cycle) of the battery. life), which is critical to maximizing battery life. “In response to these unique requirements, it is also necessary to improve memory performance and durability design. Therefore, non-volatile, high-endurance, high-speed automotive-grade FRAM is an ideal choice for BMS. At present, some Chinese customers have begun to adopt Fujitsu 3V SPI 128Kbit, 256Kbit, 2Mbit and 5V SPI 64Kbit FRAM.” Feng Yixin revealed.
Similarly, the VCU system needs to record the current state of the car and the information such as the transmission gear, acceleration, braking and output torque at a rate of once per second, while the use of FRAM can be performed by simpler software. Store and read, while ensuring high speed and high reliability. “Up to now, China’s new energy vehicles and low-speed scooter VCU systems have begun to use Fujitsu’s 64Kbit SPI FRAM.” Feng Yixin introduced, “At the same time, in May this year, Fujitsu launched the latest vehicle-grade product MB85RS2MLY, which can operate at -40°C to 10 trillion read/write times in the +125°C temperature range, ideal for applications that require real-time data logging (for example, if data is recorded every 0.1 seconds per day for 10 years, the number of writes will exceed 3 billion). High data write endurance and reliability.”
Building a solid backing for autonomous driving
With the development of automobile intelligence, more and more vehicles are equipped with autonomous driving technology. According to data from the Prospective Technology Research Institute, the domestic autonomous driving market size in 2019 is 112.5 billion yuan, and it is expected to reach 238.1 billion yuan by 2023, with a compound annual growth rate of 20%. For major car companies, new energy and autonomous driving, which are new things, can be said to start at the same time. Compared with traditional fuel vehicles, the simpler electronic control system and vehicle architecture show a high degree of fit for this combination. At present, many new new energy vehicles that have just been launched have reached the L2 autonomous driving level. “In fact, the essence of autonomous driving, or ADAS (advanced driver assistance system), is the dialogue between the car and the environment, which is realized through processes such as sensor data acquisition, memory recording data, processor operation data, and feedback. To be completed in a very short time, in addition to high speed, the key of the key – reliability must be guaranteed!” Feng Yixin said when talking about autonomous driving technology.
Three core technologies of autonomous driving
ADAS is the prelude to autonomous driving and the core of the current market. While autonomous driving continues to grab the headlines, ADAS, an advanced driver assistance system, has quietly set off a wave of change, fundamentally changing the way traditional cars are handled and the user experience. The redundancy and fault-tolerance characteristics of autonomous driving require that the higher the level of autonomous driving, the more sensors are required. Feng Yixin pointed out: “All subsystems of ADAS, such as sensors, cameras, CAN communication, in-vehicle HMI, etc., must store current status information in real time and continuously for real-time monitoring, recording, analysis or processing. Volatile, high-speed write, and high write endurance FRAM memory just meets the reliability and latency-free requirements of autonomous driving! Therefore, as ADAS technology becomes more mature, FRAM opportunities in this field are also increasing Big.”
Taking the application of intelligent airbags in artificial intelligence decision-making platforms as an example, airbags, as a must-have configuration of most cars, play a great role in ensuring the personal safety of drivers and passengers. For smart airbags, after the airbags are activated, the system should continuously record whether the airbags operate normally and the action history data of the airbags, and finally use these data as legal basis to deal with accidents and investigate the causes and responsibilities; in addition, the system also needs to real-time Empty seat information and passenger weight are monitored and continuously recorded to ensure accurate and timely airbag activation. “These requirements make FRAM an ideal choice. At present, Tier1 continental has adopted FRAM in their smart airbags, and some customers in China have also adopted 16Kbit serial FRAM.” Feng Yixin revealed.
Application of FRAM in Smart Airbag
In addition, in the tire pressure monitoring (TPMS) application in the ADAS segment, Fujitsu has taken the first step to seize the automotive application market. According to reports, Fujitsu FRAM memory has been adopted by Pirelli tires for the first time in the TPMS system of its automobile tires to achieve reliable low power consumption, high-speed writing and high-durability data processing functions. Pirelli is one of the most famous tire companies in the world. Pirelli tires with a history of more than 100 years have become synonymous with “reliable quality” and “excellent performance” in the tire industry! In this regard, Feng Yixin said: “TPMS should monitor the tire pressure in real time and continuously, and if there is insufficient inflation, an alarm will be issued immediately. The tire pressure monitoring is installed in a harsh environment with high temperature and high pressure, and the battery is not easy to replace. In order to prolong the battery life , the use of low-power memory is a must. These requirements make FRAM ideal for tire pressure monitoring.”
Cost competition, is FRAM really expensive?
Although FRAM has more advantages than traditional Flash and EEPROM in terms of read and write endurance, write speed and power consumption, it also has the disadvantages of high cost and low capacity. “Generally speaking, some manufacturers may choose EEPROM instead of FRAM due to cost factors, but it may not really save costs.” Feng Yixin explained, “They often do not realize that FRAM and EEPROM work. Huge difference.”
FRAM has better endurance than EEPROM
As shown in the figure above, the number of writes to FRAM is about 10 times that of EEPROM7times, which means that the latter requires a much larger overall capacity for the same number of writes. Assuming FRAM is 4KB, although small, it allows 10 to be written repeatedly in the same area of the entire block of memory13secondary data. On the contrary, the EEPROM capacity can be much larger than 4KB, but is limited by the number of writes (only 106times), if area A in the entire memory reaches the limit of the number of writes, the stable writing of data in area A will not be guaranteed, and another area B needs to be rewritten; then the replacement process of the new and old areas requires Wear Leveling ( wear leveling technology) to control, which virtually increases the cost of software configuration.
In addition, the writing speed of FRAM is about 30,000 times that of EEPROM. When special circumstances such as power failure occur, the former can write data and save it in a very short time (about 0.00015ms), while the latter can ensure that the data is still in the moment of power failure. To be able to record data, it is often necessary to use supercapacitors to “supplement” the circuit, which is another cost. Moreover, in order to reserve sufficient number of writes, especially in applications such as BMS that frequently record data, the greater the capacity requirement of EEPROM, the higher the cost. In other words, the cost of EEPROM is equivalent to its own capacity + capacitance + software, so compared with FRAM, there is not much cost advantage.
Car infotainment with EEPROM
In addition, FRAM is capable of not only high-speed writing, but also high-speed erasing. In this regard, low-power and high-speed FRAM can use small battery power to instantly erase important data, thereby ensuring user information security. At this time, FRAM only needs a working current of 0.1mA to erase 256bit data in 0.3ms, which has a significant advantage over EEPROM.
Comparison of working current and erasing time of FRAM, EEPROM and FLASH
Because the Chinese auto market started relatively late, in relatively mature auto markets such as Europe, America, Japan and South Korea, there are already relatively concentrated auto brands, perhaps only three or four. In the Chinese market, there are still hundreds of auto brands with different needs. different. “If Chinese companies want to beat their opponents or try to stand in the same position, they need to keep up with international vehicle standards and choose better quality and more reliable electronic components to design and manufacture more advanced products.” Feng Yixin Said, “By adopting Fujitsu FRAM, car companies will no longer have to worry about key data storage!”