Due to the technical blockade of high-tech in the United States, epidemic situation and other factors, foreign MCU began to be out of stock recently. According to the insiders, the products of international MCU manufacturers have been postponed, and the new orders are basically not accepted. Some people joked that the increase of chip price has exceeded the price of Shenzhen house. What are the key elements of domestic substitution? How to create an industrial grade accurate and reliable light of domestic products?
The customer originally used 4 * 2 matrix products made of foreign chips. The products of Xinhai technology can be directly replaced without changing any hardware, and the compiling environment also needs not to be changed. Just choose the chip model cs32f030c8t6. After the replacement, the effect and performance are the same as those of foreign chips.
It seems very simple to complete the replacement in two minutes, but it requires a lot of accumulation of conditions. Pin compatibility is very important, but it is only the tip of the iceberg. If we want to make a long-term product, we must start from quality assurance, supply capability, system operation efficiency, development ecology, chip reliability, clock stability, anti-interference capability, ADC performance, tool chain And other factors.
Recently, foreign MCU began to be out of stock. According to the industry, the products of international MCU manufacturers have been postponed, and the new orders have not been accepted. Some people joked that the price of chips has exceeded the price of Shenzhen house. What are the key elements of domestic substitution? How to create an industrial grade accurate and reliable light of domestic products?
Quality advantage, product quality is reliable
China''s IC industry started late, the lack of core technology, and the lack of local design capacity, resulting in a large demand for chips in China mainly rely on imports, the overall development level is far behind the western developed countries, domestic substitution, product performance is the premise. After years of development, Xinhai Technology has accumulated rich R & D experience, professional technology and management team, and corresponding reserves in market, personnel, technology, management experience, etc.
What is true pin compatibility?
First of all, pin compatibility is not only consistent with pin definition, but also has many implied indicators. In terms of design capability or architecture, there are often subtle differences in design and benchmarking. For example, in domestic substitution, the internal power supply of a certain manufacturer needs external circuit to assist stability, while the foreign one doesn''t need this component, so it takes up one more pin, which leads to the board can''t be used, so it has to draw a separate circuit to add a capacitor for processing It''s not very big, but it will make the replacement cycle very long.
The second is some hidden electrical characteristics, such as reverse voltage withstand. One of the key characteristics of f030 / 031 is that when VDD = 3.3V, IO supports 5V input. If it does not support the characteristics, it is easy to cause current backflow and affect the reliability. So we must pay attention to whether the scene is used, and if so, whether the chip used has this function.
The third is power consumption, which is different from design and process. The impact of excessive power consumption: 1. Beyond the scope of hardware design, affecting stability; 2. Heating, affecting performance and reliability; 3. In battery applications, shortening battery life. From the perspective of architecture, process, design and other power consumption characteristics, Xinhai Technology is slightly better than its friends.
Pin compatibility is not the same package size or definition, but the electrical characteristics and performance behind it should be consistent.
Is 12 bit ADC the same as 12 bit ADC?
We are all targeting 12 bit ADC, but the difference is particularly large. The figure below clearly shows the difference in resolution and accuracy. The average value of a''s shooting normal distribution is biased and very discrete, which is called low resolution and accuracy; B''s distribution around the target center is accurate, with good accuracy, but the resolution is not enough, so it can''t hit 10 rings; C''s very dense, with accurate shooting, but it''s all biased, with high resolution, but not enough accuracy; some manufacturers publicize ADCs 12 bit or even 16 bit, but it only improves the resolution D is a real ADC with high resolution and high precision, and its density is concentrated and accurate.
How to reflect the accuracy of ADC, we can focus on these indicators: the first indicator is absolute error, which refers to the error of the product in the uncalibrated state, which can reflect the basic characteristics of ADC; the second indicator is offset error; the third indicator is gain error, which comes from the amplification factor, which can be simply understood as a slope deviation; the fourth indicator is differential non-linear The fifth index is integral nonlinearity (inl), which is not only the most important index, but also the most basic index reflecting the accuracy of ADC. If the inl index is good, other parameters will not be too bad.
The inl of Xinhai technology can achieve 1.2lsb, that is to say, a 12 bit ADC can achieve 11 bit or even better performance after calibration and adjustment in the measurement process, and 11.5a or even higher performance after conversion. For the same ADC, the peer may do 8-bit and 9-bit, because the quality is guaranteed. Whether it is measuring voltage or current, if we use our ADC, we will be more assured.
Can ESD index represent reliability?
Product quality and reliability are very important. When some enterprises publicize reliability, they will say how many volts ESD is and whether ESD index can represent reliability? There are many factors in reliability, which can not be represented by only one ESD. ESD only represents static anti-static capability, such as HBM, mm and CDM, which represents static anti-static capability of IC. In the standard production environment, 2KV can meet the demand; in the non-standard production environment, 4KV can protect the process from damage. The ESD parameters in foreign countries can be written as 2000V, because the production environment of foreign customers is very standardized, 2000V can meet the basic needs. In fact, 2000V is not enough in China. Some protective devices need to be added. Basically, 4000V can ensure that the whole production process will not be damaged and the yield is guaranteed. High ESD may be useful, but it does not represent the real reliability of the product. In addition to ESD, it also needs to consider from the aspects of functional safety, temperature characteristics (whether it can ensure reliable operation under the working temperature, and the key modules are not accurate after the temperature changes), reliable measurement (whether the ADC accuracy is guaranteed under harsh environment), package reliability, board level reliability, etc.
Cs32f030 is a typical functional safety product, which has done a lot of reliability design (key register protection, flash storage protection, SRAM storage protection, clock protection, watchdog, ADC reliable measurement, IO level self-test). Protection of key registers: when ESD is executed, electrostatic interference that may not be completely eliminated will rewrite the calculator. If it is not handled, it will lead to errors in the whole system, and we don''t know what kind of errors will occur. Therefore, we have made protection on many key computers to prevent rewriting. Even if it is rewritten, we can know that the software can perform corresponding processing Li. Storage protection: our flash internal is to do the hardware verification, can also be built-in CRC module to do software verification, you can know whether the program is wrong in it. The IC is not 100% reliable, there is no error, zero defect to pass
There are many measures to protect the chip. Clock protection: clock is a very important part of MCU. If the clock goes wrong, no matter how good the chip is, it is useless. We have made clock and detection devices. We use external clock when designing. If the clock stops vibrating or fails, we can go to the internal clock to do some basic safety treatment. For example, when the wharf is running, we can make it stop slowly, which will not cause safety accidents.
Ambient temperature refers to the temperature of the external environment; the chip is packaged, there is a process of heat dissipation, there may be temperature difference between inside and outside, the junction temperature can be understood as the temperature of the internal wafer. The whole series of our chips are designed according to the junction temperature of 125 ℃. The cs32f030 / 031 series supports the working temperature of 105 ℃ and the junction temperature of 125 ℃ to ensure the high reliability of the environment. In mass production, each chip will do the high temperature test of 110 ℃ to ensure the reliability of the chip.
Without a plug-in crystal oscillator, if an internal clock is used, the internal clock will have a temperature characteristic, because the internal clocks are all built up by resistance and capacitance circuits. For example, an 8-megabyte internal clock may be 7.99 megabytes at 25 ℃, but it will drift at 85 ℃. When we did the clock design, we did a lot of temperature compensation and temperature drift prevention features, including some voltage compensation circuits, which made the temperature characteristics particularly good. Through the anti temperature drift design, the internal clock temperature drift of cs32f031 is controlled within 1%, which meets the requirements of UART and other communication, and effectively reduces the measurement error caused by clock drift. Some people may be curious to run a program, what is the use of high precision, for example, asynchronous communication, once your clock deviates, beyond a valid range, in fact, your communication will fail.
ADC measurement will use an internal benchmark to make a comparison. If there is no external benchmark, these temperature characteristics of the internal benchmark represent your test accuracy. Our benchmark is based on 60ppm. The deviation of voltage per degree centigrade is not more than 60 ppm. In China, some are 100, some are 200, and some are not standardized. However, it is a very important point in measurement.
Reliability is guaranteed by many links. The reliability of Xinhai Technology is based on demand, such as customer demand, industry standard and internal standard. All products will be tested at chip level, including MSL, uhast and board level HTOL. The cost of these tests is very high, and it may cost more than 100000 yuan or even more to test a cycle. In the process of MCU chip research and development, chip investment only accounts for a small part, and the cost of design and reliability is very large. We have a very detailed management process and reliability test indicators, which will be customized according to different industrial and mobile phone categories. We will make strategies according to years of accumulation, customer communication and industry characteristics.
Reliability is not only guaranteed by ESD system. The quality control of reliability test of Xinhai Technology is very strict. It has established in-depth strategic cooperation with mainstream distributors in the main business fields of the company''s main channel. Through strict certification of first-class customers and leading enterprises in the industry, it has built a good customer relationship and selected our products with guaranteed quality.
Can 100% testing guarantee quality?
100% testing for mass production of chips is a pseudo concept. Every chip has been tested, which is the first 100%. The scope specified in the specification has been tested, which is the second 100%. With the increasing scale of chips, 100% testing is impossible. Mass production test is only the last link of quality assurance, more importantly, the guarantee of the whole system.
Returning to the production management system at the executive level, we will have a whole process management and control. From the beginning of wafer processing, the wafer manufacturing of any product is not 100% stable, and there will be some process deviation. We will monitor this process deviation in real time to prevent quality abnormality from the source. CP, packaging, FT + DS, including warehousing quality management, shipping process management will have a series of control. We have an internal slogan "quality is designed". Quality is not tested. The whole R & D process will always control the quality from the demand stage. With 17 years of experience, Xinhai Technology will iterate the historical experience into each generation of products.
Quality is a systematic project. Our quality control not only depends on testing to ensure the quality of products, but also through systematic management measures from the management level to the executive level to various reviews. It is a higher quality control than 100% testing, and the product quality is reliable.
Supply guarantee, continuous delivery capability
The whole process of wafer processing, packaging and testing takes 4-6 months. At present, affected by the international situation and epidemic situation, the cycle is longer. Delivery capability has high requirements for the capital strength, supply chain management capability and system operation efficiency of semiconductor enterprises. Through the construction of excellent supply chain management system, Xinhai Technology constructs three lines of defense for supply guarantee from demand management, inventory planning and supply execution. Demand management is the first line of defense, according to the normal situation of customer demand forecast, or even do some more forecast to prepare. The second line of defense is the inventory plan, which is expected very early and makes the safety stock plan to establish the safety stock. The third line of defense is a series of internal management systems to mobilize resources and give play to the combat effectiveness of the supply chain. Only the joint efforts of the three lines of defense can guarantee the delivery under abnormal circumstances and solve the supply problem that everyone is worried about.
As the brain and heart of electronic products, MCU chip is the cornerstone of information security and the basic guarantee of national security. Under the environment of Global trade protection and Western countries'' blockade of chip export to China, Chinese science and technology enterprises must come up with solutions. As a leading enterprise of full signal chain chip design integrating sensing, computing and control, Xinhai Technology has been polishing products with industrial standard for 17 years. It has accumulated more than 10 years in the field of MCU. It has a deep understanding of high-precision ADC and high reliable MCU technology, mastered full signal chain chip design technology and built a perfect development ecology. In the future, Xinhai Technology will focus on the R & D and design of high-precision ADC, high-performance MCU, measurement algorithm and one-stop solution for the Internet of things, continue to plough deep into the field of signal chain chip, give full play to the advantages of ADC + MCU dual platform, and bring greater imagination space for future domestic substitution.