Smart Times Murata Medical uses RFID solutions to help the construction of smart medical care

In recent years, driven by national policies and technologies, my country’s smart medical market demand has continued to grow, and the market scale has expanded rapidly. According to the “2019 China Smart Medical Industry Market Prospect Research Report” released by the China Business Industry Research Institute, the sales scale of China’s smart medical market exceeded 70 billion yuan in 2018, and it is expected to approach 120 billion yuan by 2020. The broad development prospects of the smart medical market are attracting more and more companies to join it. As a world-renowned Electronic component manufacturer, Murata Manufacturing Co., Ltd. (hereinafter referred to as “Murata”) responds by providing small and highly reliable products. The development needs of the smart medical field.

Murata Medical RFID Solutions: Helping the Construction of the Medical Internet of Things

RFID (Radio Frequency Identification, Radio Frequency Identification) technology has the advantages of long identification distance, short reading time, high accuracy, and large data storage capacity. Only one tag can provide an integrated solution. In recent years, medical sample management has been widely used. , tracking and other fields have been more and more widely used. Murata can provide a series of high-quality antennas, readers, and software solutions, including RFID equipment.

Taking medical device management applications as an example, with the strengthening of UDI (Unique Device IdenTIficaTIon) regulations, the demand for serial number management of medical devices is booming, and Murata has timely launched RFID tags for surgical devices. This product is a new type of metal-resistant UHF RFID tag with a size of only 6x2x2.3mm, which can be attached to most surgical instruments. It is a UHF RFID tag with small size and powerful performance in similar applications.

　　Smart Times Murata Medical uses RFID solutions to help the construction of smart medical care

Surgical instruments with Murata RFID tags installed

This product uses the metal surface of the object as a booster for the antenna. Through the cooperation with Nanjing Langdengjie Medical Technology Co., Ltd., it is fixed on the surgical instrument with a special fixing method with high strength, which can withstand the impact of more than IP 65 level. Attached to the biofilm that has passed the biocompatibility compliance test of German TUV and China Medical Device Inspection Center. The product can read information in batches in the closed-loop circulation of surgical instruments for efficient management, even if the surface is blood-stained or pre-soaked wet instruments can be read.

In addition, Murata’s ultra-small RFID/NFC tags (3.2×3.2×0.7mm) can also be attached to test tubes and petri dishes to realize automatic detection, counting, verification, identification and other management, effectively improving blood sample testing and experimental efficiency. Fast reading even in low temperature and humid environments for fast detection.

　　

Application of RFID tags on test tubes

Murata’s medical-grade components: diverse varieties and reliable performance

As a company that designs and manufactures advanced electronic components and multi-functional high-density modules using electronic raw materials with excellent performance, Murata has a history of more than 70 years and has developed a variety of electronic component products to fully meet the needs of smart medical Different scenarios and different types of usage requirements in the field.

Murata’s high-density silicon capacitors are thin, highly reliable, and have high stability in terms of voltage, temperature, aging, and electrostatic capacitance values. They can be used in pacemakers, defibrillators, plug-in nerve stimulation devices, and artificial organs. , prostheses (artificial heart, artificial retina, myoelectric prosthesis, etc.), life support equipment and other fields are being implanted by more and more pacemakers, hearing aids, monitoring equipment, eye implants, etc. in the European and American markets. Accepted by classified medical clients.

　　

Murata MGSC Series Medical Silicon Capacitors

In recent years, the data communication of medical devices has become increasingly popular. For example, devices such as patch-type blood glucose meters, insulin injection pens, nebulizers, etc., which can continuously measure blood sugar levels without drawing blood, can continuously measure the number of administrations, doses, patient temperature and other vital signs, and use mobile devices to make Patients and doctors can observe progress in real time and understand the patient’s living habits. Data from these measurements is sent to mobile devices via Bluetooth Low Energy (BLE), a short-range wireless communication technology. Such medical devices not only need to be equipped with communication functions, but also need to be small and long-running. However, the contradiction between shrinking the size of the components and increasing the size of the battery has caused designers to struggle, and Murata’s resonator products meet these conditions with superior performance.

　　

Murata’s MEMS resonators for medical devices

Murata’s MEMS resonators use MEMS technology to achieve ultra-small size and low ESR characteristics that cannot be achieved by crystal resonators. This product achieves good frequency accuracy and temperature characteristics of the resonator without compensating for the initial accuracy and temperature characteristics of the active element, contributing to low power consumption and reduction of mounting area for customers, and is suitable for small and thin devices.

With the advent of the Internet + era, China’s medical industry is transforming and upgrading in the direction of intelligence and digitization. In the future, Murata will provide more and more innovative products and solutions to help the construction of smart hospitals, create a more secure and convenient medical environment, and work with all sectors of the industry to promote the development of China’s smart medical industry.

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Digi-Key Launches “Revolutionizing Automation” Video Series Exploring Cutting-Edge Automation and Control Technologies

[Introduction]Digi-Key has launched a new video series “Revolutionizing Automation” exploring cutting-edge automation and control technology. Powered by Omron and Siemens, this four-episode video series highlights how Digi-Key processes more than 5.3 million orders per year through an efficient supply chain that collaborates with many of the world’s leading suppliers Transform automation and control solutions including sensors, motors and controllers, robotics, connectors, power supplies, RFID and more.

Digi-Key is releasing a four-part video series titled Revolutionizing Automation with Omron and Siemens.

Eric Wendt, Director of Automation at Digi-Key, said: “Automation and control components are not only products in Digi-Key’s broad portfolio, they are the products we use every day to ensure fast, safe and efficient order fulfillment. Automation and control are A fast-growing market is critical to ensuring that global supply chains run smoothly through the ups and downs, so we are excited to share more about Digi-Key’s use of this technology in this video series.”

The first video in the video series, Totally Integrated Automation, is now live on the Digi-Key website. Based on interviews with Siemens leadership, this episode explores the various building blocks for Totally Integrated Automation, which are now available to Digi-Key customers.

In the second episode, Robots and Machinery, we show how Digi-Key leverages robotics from Omron and others to automate Digi-Key’s entire warehouse tasks. The episode is expected to be released in early April.

In late April, our third episode, Inventory Management and Sorting, visits Digi-Key’s new distribution center, which manages the industry’s largest in-stock electronics inventory, and highlights how Siemens products are helping automate the operation of this new facility of.

The fourth and final video in the series, titled “Efficiency and Worker Safety,” will launch in May and will focus on the many ways in which Omron’s automation solutions are used to simplify everyday tasks to keep workers safe.

Mark Binder, Director of Channels at Omron, noted: “The topic of automation has a long and storied history of enabling factories to increase productivity, increase flexibility and reduce work responsibilities. As innovation continues to drive manufacturers to automate more processes, finding a The right partner is essential to provide integrated, intelligent and interactive solutions. As a leader in automation technology, with solutions covering the entire production process, Omron is consistently committed to helping system integrators and machine builders cope with the constant changing needs while ensuring operational excellence.”

Kurt Covine, Director of Partner Sales at Siemens Digital Industries, said: “The future of this industry is here. Automation goes hand in hand with the digitization of production. Digitization can give businesses powerful competitive advantages such as greater flexibility, minimal downtime and improved productivity. High quality. Our resources are limited, and we need to do more with less. Partnering with Digi-Key gives our customers access to Siemens’ latest automation solutions to meet this challenge and realize the promise of digitalization.”

To watch this video series and learn how Digi-Key is revolutionizing the future of automation and control, visit the Digi-Key website.

About Omron

Omron Automation is a global leader in automation technology. We have the world’s most comprehensive product portfolio covering sensing, control, safety, vision, motion, robotics and services. We are passionate about innovation, have a soft spot for automation, and strive to create an environment where people and machines live in harmony. Our focus is on developing next-generation technologies to provide integrated solutions that optimize machines, production lines and businesses – making manufacturing safer and more efficient. With more than 30,000 employees in more than 120 countries, wherever your needs are, we provide you with local professional service and support around the world. With our proof-of-concept centers around the world, we have earned our customers the confidence that our solutions will work for the future they are building, and give them the freedom to start now and do what they do best – building world-class products .

About Siemens

Siemens Corporation is the US subsidiary of global technology giant Siemens AG, which has distinguished itself in the industry for more than 170 years with engineering excellence, relentless pursuit of innovation, quality, reliability and broad international reach. The company operates globally, focusing on intelligent infrastructure for buildings and distributed energy systems, as well as automation and digitalization for process and manufacturing. Siemens is committed to promoting the convergence of the digital world and the physical world to achieve inclusive benefits for customers and society as a whole.

About Digi-Key Electronics

Digi-Key Electronics is a global full-service authorized distributor of Electronic components, headquartered in Thief River Falls, Minnesota, USA, and distributes more than 10.2 million products from more than 2,200 premium brand manufacturers. Digi-Key also offers a wide variety of online resources such as EDA and design tools, datasheets, reference designs, instructional articles and videos, multimedia libraries, and more. 24/7 technical support via email, phone and live chat. For additional information or access to the world’s most extensive technology innovation resources, please visit www.digikey.cn and follow our WeChat, Weibo, Tencent Video and BiliBili accounts.

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The independent process of the domestic operating system, the self-improvement road of the information security of a big country!

On the occasion of the 100th anniversary of the founding of the Communist Party of China, the State-owned Assets Supervision and Administration Commission of the State Council and the Central Radio and Television Station jointly launched a 100-episode micro-documentary “Century of Tokens”. Taking the “red token” as the starting point, 100 state-owned enterprises represented by central enterprises The person in charge of the party committee (party group) introduced the company’s heirlooms, and revealed the little-known moving stories behind the company’s surging development through the history of material evidence. Seeing people, objects, and spirit, carrying forward the red tradition and inheriting the red gene .

　　

Today, I would like to share with you the 23rd episode of “The Chinese Operating System to Protect Information Security” of “Century of 100 Years”, and listen to Rui Xiaowu, Secretary of the Party Group and Chairman of China Electronics, tell the story behind the domestic operating system.

　

　

Rui Xiaowu, the narrator of the token, said: “The operating system is invisible and intangible, but it is everywhere. It is the soul of the computer and the foundation of the network security of a great country. Only a country can have its own right to speak in the field of information security. Starting from this software, the long journey of China Electronics to build an independent operating system has set sail.”

Today, let’s follow Rui Xiaowu, the narrator of the token, to learn about the story of China Electronics continuing to inherit the red blood since the birth of China’s first Chinese operating system, creating the Kylin operating system, and protecting national information security.

　　The information technology revolution sweeps the world

Chinese self-built operating system set sail

In the early 1980s, the information technology revolution swept the world. Across the ocean, personal computers have officially opened up the commercial market and entered the public eye. In China at the beginning of the reform, although computers have just begun to appear in the field of scientific research, it has already shown the great possibility of information changing production and life. At this time, the computers still run the pure English DOS system of Microsoft Corporation. isolated.

　　

▲In 1983, China’s first PC operating system, CCDOS, was born in China Electronics.

In order to overcome this problem, Chinese software engineers developed China’s first Chinese operating system CCDOS in 1983, realizing the localization of the operating system. The language problem has been solved, but for China’s information industry, there is a bigger problem that needs to be solved urgently, that is, the problem of core codes.

　20 million+ lines of code

A new generation of domestic operating system “Kylin” came out

The operating system is like the foundation, and the information is in the house above. If you master the operating system, it is equivalent to entering the house from the foundation and obtaining the most important data information. If China’s information industry does not have an independent operating system and has been living on the “foundation” of others, where can the information security of individuals and the country be discussed?

In 2002, engineers from the nation’s top information institutes chose a system design that integrated four different technical architectures.

This is an extremely complex structure, full of helplessness and compromise of engineers. Their experience, manpower and time are seriously insufficient, and they can only adopt the most stupid way and take the most complicated way. The four kinds of system kernel codes have nearly 20 million lines, and if printed on A4 paper, they can be stacked more than 70 meters high. Faced with such a huge workload, engineers often write code for more than ten days and nights, and use the laboratory computer room as their home.

After more than four years of fierce battles, a new generation of China’s domestic operating system has finally been successfully developed.

　

▲In 2006, the news network reported that my country had completed the development of the world’s advanced “Galaxy Kylin” server operating system.

Rui Xiaowu, the narrator of the token, said: “This operating system, which has been polished through countless hardships, holds everyone’s expectations. It is like a newborn baby, which makes people happy. How to name this ‘newborn’, everyone It was difficult for a while. In the end, there is such a name, which draws on the strengths of the four codes, and has the same characteristics as the traditional Chinese mythical beast – the unicorn with lion head, antlers, elk body, and ox tail, so, there is Our household name now: Kirin.”

But the autonomous operating system is not just running in the laboratory, it needs to face the test of the market. Soon, Kirin ushered in its debut in the market. The ticketing system of China Civil Aviation Information Group has always used foreign operating systems and databases, but when renewing the contract, foreign manufacturers made a big splash and offered ten times higher prices than before. China Civil Aviation Information Group began to seek domestic replacement products. The civil aviation ticketing system is the nerve center of China’s civil aviation. The huge transaction volume it generates every day is an unprecedented challenge for the fledgling Kirin. The Kirin team decided to take three steps:

First, the Kylin operating system was tested on Tibet Airlines, which has less passenger traffic, and it was successful.

Then, Capital Airlines, everything went smoothly.

Finally, the Kylin operating system ushered in the big test. The object of this service is Air China. As the largest domestic airline, its data processing is far ahead of the first two airlines, which means that the system background workload will increase exponentially. After the test, the technicians couldn’t help but sweat.

In order to ensure the smooth operation of the system, all the operation and maintenance experts are on duty throughout the night, all eyes are fixed on the screen in front of them, 24 hours of uninterrupted testing and maintenance, one day, two days, one week, two weeks… on the screen The data and the back-end system show that everything is normal, and all transaction data are accurate. Finally, Kirin passed the test perfectly.

　

▲In 2016, Kylin OS became the first domestic OS to serve the core business of civil aviation.

　Guard the information security of a great country

Help my country’s modernization development

The Kirin operating system, which has been successfully applied in the core field, has matured in the tempering of the market, and has gradually entered into serving other more important production and life fields. It used to struggle, but now it has spread across industries such as transportation, finance, energy, and public services. Among millions of computers, Pentium has laid a “China foundation” for information security for all walks of life in rapid development.

　

▲ In 2021, Galaxy Kirin operating system desktop environment.

Rui Xiaowu, the narrator of the token, said emotionally: “After more than 30 years of hard work, the Kylin operating system has finally come to fruition, not only serving all aspects of our lives, but also in Chang’e lunar exploration, Tianwen No. 1 and other big countries that make our people proud. In the heavy equipment. As its safe and reliable backing, it is this string of ever-changing ‘codes’ that guards the security of major countries and injects galloping power into my country’s modernization development.”

In 1983, China’s first PC operating system, CCDOS, was born in China Electronics.

In 2000, Chinasoft Linux became the first domestic operating system to be applied to government agencies on a large scale.

In 2016, Kylin OS became the first domestic OS to serve the core business of civil aviation.

In 2018, Kylin OS won the first prize of the only National Science and Technology Progress Award in the field of operating systems in the history of New China.

In 2021, the flight control system supported by the Kirin operating system will operate stably, ensuring the smooth landing of Tianwen-1 on Mars.

　The first Chinese operating system from China

to Kylin OS

In the torrent of the development of the times

Chinese Electronic people always adhere to the original intention

full of enthusiasm

shoulder the burden of the mission

Taking core technology innovation as its own responsibility

In order to speed up the construction of the national network information industry

Core strength and organizational platform contribution

　　

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Does academic evaluation focus on journal impact factor?It’s still a college ill

A survey of North American research institutes found that 40 percent of research-intensive universities mentioned a controversial metric, the impact factor, in their assessment documents.

The journal impact factor refers to “the total number of citations of papers published in a journal in the previous two years divided by the total number of papers published in the journal in those two years”. The impact factor has become a commonly used journal evaluation index in the world, but is it a scientific approach to use the impact factor to judge the importance of a study, and even to judge the research ability of researchers?

The impact factor is the average number of citations for all papers in a journal, and it does not reflect the citations of every study. So a journal with a high impact factor means that it has many highly cited articles, but it cannot mean that every study is highly cited.

In recent years, many scholars and researchers have criticized the practice of academic evaluation based on impact factors, believing that it is unfair. In addition, many university teachers are also thinking about how to balance scientific research and teaching. It is unfair to only use scientific research as the main criterion for employee evaluation and promotion. The evaluation should take into account the contribution of researchers outside of scientific research.

However, many research institutes still use the impact factor as an important indicator for academic evaluation and job promotion. A survey of North American institutions found that almost half of research-intensive universities consider journal impact factors when determining promotions.

According to a survey of more than 800 documents from 129 institutions in the US and Canada, about 40% of research-focused institutions mention impact factors in their assessment, promotion, and tenure documents (RPT documents).

The data shows that many universities use the “impact factor” to assess faculty performance, which has been widely criticized as a crude and misleading measure of research quality.

“It shows that these institutions may not be thinking correctly about what kind of teachers they want,” said Elizabeth Gadd, research strategy manager at Loughborough University, UK.

Measuring Impact with Journal Impact Factors

The Journal Impact Factor measures the average number of citations to articles published in a given journal over the past two years. Publishers often use this number in bids to advertise the quality of the journal. However, many academics and review groups use impact factors as a quick way to judge the quality, importance, and prestige of a study, or to evaluate the scientists who published it.

The situation has troubled many academics, who say the impact factor spreads an unhealthy and unscientific research culture, and they want universities to drop the metric in their hiring and promotion processes. Research has shown that impact factors are not very predictive of a scientist’s scientific ability, but it is unclear how often recruiters use impact factor metrics in this way.

Source: E. C. McKiernan et al. PeerJ Preprints 7, e27638v2 (2019)

To understand how widespread it is, neurophysiologist Erin McKiernan from the National Autonomous University of Mexico and colleagues collected and analyzed 864 assessment, promotion, and tenure documents from various institutions in North America for publication in the April 9 issue of PeerJ Preprints. Preprint article.

They use software to process these documents, using tools to find specific words in the documents that are associated with impact factors, and they read relevant articles in subsets of documents to understand how and why these institutions use the indicator.

Less than a quarter of institutions use a similar term, such as “high impact journal”, when referring to impact factor in such documents. But at 57 research-intensive universities, that percentage rose to 40 percent. In contrast, only 18% of universities offering master’s degrees mention journal impact factors (see chart above).

At more than 80% at very research-focused universities, the language in these documents encourages the use of impact factors in academic assessments. Only 13% of these agencies used a cautious term for this indicator. Such language may also indicate that a high impact factor is associated with better research: 61% of institutions use impact factor as a measure of research quality, and 35% say it reflects the impact, importance, or significance of research.

For example, the following sentence appears in a document from the Department of Health Management and Informatics at the University of Central Florida:

The quality and quantity of published research is important. General criteria for measuring quality include citations of papers published in highly ranked journals and research.

Similarly, a related document from the University of Vermont College of Arts and Sciences states:

Academic research is published in core journals and academic presses, which can often indicate the importance of the research.

tip of the iceberg

“Now we have some data to show the process of academic evaluation,” McKiernan said. She thinks the percentage of institutions that explicitly use impact factors in such documents may be higher, and she says the study’s findings may be “the tip of the iceberg.”

She adds that there may be more words indirectly related to impact factors in the academic evaluation process, such as “top-tier journals” or “high-ranking journals.”

A graph of vocabulary classifications associated with journal impact factors. The above figure divides the words related to the journal impact factor in the RPT file into three categories: the innermost ring is the word that directly represents the journal impact factor; the middle is the word that represents the journal’s influence to a certain extent; the outermost ring is indirect but may indicate A vocabulary of journal impact factors. The study was mainly performed on the vocabulary of the innermost and middle rings.

Stephen Curry, a structural biologist at Imperial, said it was crucial for universities to come up with new ways of assessing staff. “Researchers should be judged on the basis of their research, not just where they publish. There also needs to be recognition for their contributions beyond the publication of research articles.”

How can the academic assessment and RPT process be improved?

The lack of a necessary link between journal impact factor and quality, and the general behavior of the academic community to link the two, has led to an increasing number of behaviors and proposals to challenge journal impact factor, and they want the academic community to use the evaluation metrics responsibly, This in turn improves academic assessment.

Among them, the most famous project is the San Francisco Declaration on Research Assessment (DORA). DORA points to the many limitations of the journal impact factor and recommends against using the journal impact factor when evaluating scientists and their research, especially as a “surrogate measure of the quality of an individual research article.” DORA Advising Agency

“Clarify the criteria for staff recruitment, tenure and promotion decisions, and emphasize that the content of the paper is far more important than publication metrics or journal status, especially for early-stage researchers.”

Currently, more than 1,200 organizations and nearly 14,000 individuals around the world have signed up to DORA.

In addition, academic libraries are a major force in promoting responsible assessment indicators. Several academic libraries, including Duke University Medical Center Library & Archives, University of Illinois at Urbana-Champaign, have produced online guides to help school teachers understand how to properly use different metrics, including journal impact factors. Libraries, University of Surrey Libraries, University of York Libraries. The library also provides faculty with personal consultation and training in article publishing and bibliometrics.

Some libraries have also led related large-scale events. The Association of College & Research Libraries (ACRL) has developed a Scholarly Communication Toolkit for evaluating journals, proposing multiple ways to assess journal quality. The European Association of Research Libraries (LIBER) established the Working Group on Metrics. The MyRI project (Measuring your Research Impact) was established by three Irish university libraries to provide an open educational resource on bibliometrics.

Academic life is hard, and getting a fair and reasonable evaluation is a great consolation. It is expected that the academic evaluation and institutional RPT process will be more objective and scientific, and pay attention to the research itself and the contribution of the researchers themselves.

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What is the difference between a fully differential amplifier and a general purpose amplifier?

“Fully differential amplifiers are widely used in high-speed signal processing. This article will introduce the difference between fully differential amplifiers and general-purpose amplifiers, and simulate the working mode of fully differential amplifiers through LTspice, focusing on the input configuration design of fully differential amplifier circuits, and recommend a This software solves design pain points and efficiently implements fully differential amplifier input configuration and noise evaluation.

“

Fully differential amplifiers are widely used in high-speed signal processing. This article will introduce the difference between fully differential amplifiers and general-purpose amplifiers, and simulate the working mode of fully differential amplifiers through LTspice, focusing on the input configuration design of fully differential amplifier circuits, and recommend a This software solves design pain points and efficiently implements fully differential amplifier input configuration and noise evaluation.

1 Features and Simulation of Fully Differential Amplifier

As shown in Figure 3.31(a), the general-purpose amplifier has a set of differential input terminals (positive input, negative input), an output terminal referenced to the system ground, and two power input terminals, which are connected to the power supply system. The power terminal is usually Hidden in circuit symbols.

As shown in Figure 3.31(b), the difference between the fully differential amplifier is that the second output terminal is added to form the operation mode of differential output. The output common-mode voltage reference terminal is added to facilitate the configuration of the bias voltage range of the output signal.


Figure 3.31 General purpose amplifier and fully differential amplifier symbols

The fully differential amplifier working circuit is shown in Figure 3.32. Each output end uses a feedback resistor Rf to construct two groups of feedback loops. Each input uses an Rg as a differential input resistor, which has the following characteristics compared with general amplifier circuits during circuit operation:


Figure 3.32 Working circuit of fully differential amplifier

(1) The gain of the fully differential amplifier circuit is the ratio of Rf to Rg.
(2) The input terminal voltages (Vin+, Vin-) of the fully differential amplifier follow each other.
(3) The output range of the fully differential amplifier is doubled.
(4) The AC signals at the two output terminals (Vout+, Vout-) of the fully differential amplifier have the same frequency, the same amplitude, and a phase difference of 180°, so the even harmonics of the output signal can be canceled and the distortion of the output signal can be reduced.
(5) The average value of the DC signal at the two outputs of the fully differential amplifier is approximately equal to Vocm, but not absolutely equal. The difference between the two is defined as the output common-mode offset voltage Vos,CM. As shown in Figure 3.33, in the 25 ℃ environment, when the supply voltage is 10V, the output common mode offset voltage of the ADA4945 is typically ±5mV, and the maximum value is ±60mV.
(6) In order to evaluate the amplitude matching of the output differential signal of the fully differential amplifier, the degree of phase deviation of 180°. The concept of balance is introduced, which is equal to the output common-mode voltage divided by the output differential-mode voltage, as shown in Equation 3-13.


Figure 3.33 Vocm characteristics of ADA4945

As shown in Figure 3.34, it is the signal conditioning circuit of the ADA4945 fully differential amplifier. The working power supply is ±5V, the output common mode voltage is set to 2.5V, the common mode voltage of the two sets of input signals is 1V, and the differential mode signal amplitude is ± 50mV, the resistance error is 1%.


Figure 3.34 ADA4945 working circuit

The simulation results are shown in Figure 3.35. The signal sources V(in+) and V(in-) respectively provide sine waves with a 1V DC bias, a peak-to-peak value of 100mV, a phase difference of 180°, and a frequency of 20KHz. The output signals V(vop) and V(von) of the ADA4945 are sine waves with a peak-to-peak value of 100mV, a phase difference of 180°, and a frequency of 20KHz. There is an output common mode offset voltage of 46.67mV between the common mode signal of the output signals V(vop) and V(von) and the configured output common mode voltage Vocm. The two input pin voltages of the ADA4945 closely follow the voltage V(vip) and the difference between V(vin) is 0V. The differential mode signal output by the ADA4945 is a sine wave with a peak-to-peak value of 200mV and a frequency of 20KHz.


Figure 3.35 ADA4945 working simulation results

2 Configuration of the input terminal of the fully differential amplifier circuit

In the design of the fully differential amplifier circuit, the matching of the input interface needs to be carefully analyzed, especially the analysis steps of the single-ended signal input are very complicated. It is mainly reflected in the influence of the internal resistance of the single-ended input signal and the matching characteristic resistance on the closed-loop gain of the circuit, and the calculation process requires multiple iterations.

(1) Differential signal input structure

Figure 3.36 (a) Differential input structure, in the circuit with long transmission signal, it is necessary to use a matching resistor Rt in parallel with the input end to achieve the expected characteristic impedance RL_dm of the circuit. As shown in Figure 3.36(b), the resistance value of the matching resistor is shown in Equation 3-14.

Among them, Rin_dm is the differential mode input impedance of the circuit, because the two input terminals of the fully differential amplifier are approximately short-circuited and the input impedance is 2 times Rg. RL_dm is the expected differential mode characteristic resistance at the input.

When Rf and Rg are 500Ω, and the expected differential-mode impedance of the input terminal is 100Ω, substitute formula 3-14 to calculate the matching resistance Rt to be 111Ω.


Figure 3.36 Matching circuit of differential input structure

(2) Single-ended signal input structure

Figure 3.37 (a) is a fully differential circuit with single-ended signal input, the resistances Rg and Rf are both 500Ω, and the expected gain of the circuit is 1 times. Use a single-ended signal Vin with a peak-to-peak value of 1V to connect to the port, and the input impedance Rin is the sum of the parallel impedance of Rg, Rf, Rf and Rg, namely:

As shown in Figure 3.37(b), when the internal resistance Rs of the signal source Vin is 50Ω, the required resistance value of the matching resistance Rt is:


Figure 3.37 Fully differential circuit for single-ended input signals

As shown in Figure 3.37(b), the signal source Vin will generate a voltage divider Vi between the internal resistance Rs and the matching resistance Rt. Using Thevenin’s law, the input signal source Vin is equivalent to a signal source Vi with an internal resistance of Rts, as shown in Figure 3 .37(c). The Rts value is the parallel value of Rs and Rt. In the example, Rts is 25.96Ω and Vi is 519.23mV.

Then substitute the equivalent signal source Vi into Figure 3.37(b). In order to ensure that the impedances of the differential input terminals are equal, a resistor Rth is added to the non-inverting input terminal, and the resistance value is the same as Rts, and the circuit 3.38(a) is obtained. At this time, the output differential mode voltage of the circuit is:

There is a difference between the calculation result and the expected output voltage Vout_ideal of 1V, and it is necessary to adjust Rf to change the gain, that is, the corrected Rf value is:

Replace the Rf value with the Rf1 value, and restore the circuit before the Thevenin equivalent to obtain the final circuit structure, as shown in Figure 3.38(b). Since the Rf value is corrected from 500Ω to 1.012KΩ, the circuit input resistance Rin is transformed, and the above calculation process is reiterated. Rth1 is 25.86Ω, the generated new voltage source Vi1 is 517.188mV, and the output voltage Vout1 of the modified parameter circuit is:


Figure 3.38 Equivalent circuit of single-ended input matching

The calculation result of 0.99531V is close to the expected output voltage of 1V. In the fully differential amplifier circuit with single-ended signal input, when the expected gain is 1 times or 2 times, the parameters obtained by one iteration can be close to the expected results. The high-gain circuit design requires a huge amount of calculation, so an ADI fully differential amplifier parameter configuration software “ADI DiffAmpCalc™” is recommended.

As shown in Figure 3.39, after installing the tool, select the desired model ADA4945 through ” “, select the resistance accuracy as E96 in the “Resister Tolerance” item, select the input mode as “Terminate” in the “Topology” item, and then configure the circuit gain to 1 , Set the resistance Rg to 499Ω, input signal peak-to-peak value to 1V, signal source impedance to 50Ω, the tool will automatically calculate Rtp to be 53.6Ω, inverting input matching source resistance value to be 25.8Ω, which is close to the above theoretical calculation value.


Figure 3.39 ADI DiffAmpCalc™ tool configures ADA4945 parameters

3 Noise evaluation of fully differential amplifier circuit

Noise analysis of fully differential amplifier circuits is more complicated than gain configuration. Figure 3.40 shows the differential circuit noise model of the ADA4945-1, including the voltage noise VnIN converted to the input, the current noise inIN- and inIN+ (assumed to be equal), and the noise voltage is generated by the parallel combination of the gain resistor and the feedback resistor. VnCM is the noise voltage density of the VOCM pin. Noise generated by each resistor.


Figure 3.40 ADA4945 circuit noise model

The type of noise used at the input end of the fully differential amplifier is converted to the relationship between the noise at the output end, as shown in Figure 3.41.

Among them, the noise gain Gn is Equation 3-15.

The feedback factor β1 is formula 3-16, and β2 is formula 3-17.

When RF1 and RF2, RG1 and RG2 are completely matched, β1 and β2 are the same, set as β, and substituted into Equation 3-15 to get Equation 3-18.

At this point the VOCM output noise becomes zero. The total output noise, VnOD, is the rms sum of each output noise term, as shown in Equation 3-19.


Figure 3. 41 ADA4945 circuit noise voltage density

However, the noise analysis of the fully differential amplifier circuit is not an independent parameter calculation, it will involve the adjustment of the gain, the adjustment of the gain resistance and the feedback resistance, and these adjustments will also affect the power consumption of the circuit. The calculation process requires a lot of iterations, and the resulting calculation work The amount is amazing. Compared with the configuration shown in Figure 3.37, the configuration shown in Figure 3.42 reduces the noise RMS value by 34.9uV, but the power consumption increases by 27mW.


Figure 3.42 ADA4945 circuit configuration Rg is 200 noise calculation results with a gain of 1

To sum up, in the design and evaluation of fully differential amplifiers, it is recommended that people who have auxiliary tools should use auxiliary tools for evaluation. The author has gone through a detour here. When I was engaged in research and development in 2011, I used the ADA4932 to design a three-stage amplifier circuit in a high-speed acquisition board, including 5 times the single-ended to differential gain, 2 times the full differential gain, and 1 time the full differential gain. Especially in the design of the input terminal configuration of the single-ended to differential gain of 5 times, after several days of calculating multiple sets of data to prepare for evaluation, when sitting proudly in front of the test bench and preparing for verification, I suddenly realized that the standard resistance was neglected in the iterative process. The results of these calculations can only be achieved by splicing resistors. A rush of blood rushed to Tianmen acupoint in an instant, and thousands of mythical beasts rushed past in my heart. I deeply understand that the essential difference between humans and animals is to make and use tools! So , again the ADI DiffAmpCalc™ tool is recommended.

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Checking Amplifiers for EMI Issues Using EMIRR Specifications

As technology advances, EMI poses an increasing threat to the proper functioning of circuits. This is because Electronic applications are moving to various wireless communication or portable platforms. Therefore, most of the disturbing EMI signals end up in the PCB trace in the form of conducted EMI.

When you try to design an anti-EMI circuit, you will find that the analog sensor circuit tends to be a huge EMI absorber. This is because sensor circuits often generate low-level signals and have many high-impedance analog ports. Additionally, these circuits use tighter component spacing, which makes it easier for the system to capture and conduct noise interference into the traces.

In this EMI situation, the operational amplifier (op amp) becomes a prime target. We’re in Part 1 of this series of articles”EMI How to interfere with a circuit through a medium“I saw this effect. (For details of the article, please refer to TI’s official website:http://www.ti.com.cn/general/cn/docs/gencontent.tsp?contentId=152156 ), the EMI signal shown in Figure 1 in this article causes an offset voltage error of 1.5 volts!

A standard op amp has 3 low-impedance pins (positive power, negative power, and output) and 2 high-impedance input pins (see Figure 1a). Although these pins are resistant to EMI, the input pins are the most vulnerable.

picture1 EMIRR andEMIRR IN+ Comparison of measurement methods

EMIRR EMI rejection ratio

The characteristics of the inverting and non-inverting pins of a voltage feedback amplifier are basically the same.However, the non-inverting input (seepicture1b) is the easiest to test for amplifier EMI tolerance.

(1)

In Equation 1, VRF_PEAK is the peak value of the RF voltage used, VOS is the DC offset voltage of the amplifier, and 100 mVP 100 mVP Input signal EMIRR IN+ reference.

You can use the EMIRR metric to compare the EMI suppression performance of amplifiers.picture2 The EMIRR IN+ response of the TI OPA333 CMOS op amp is shown. The graph shows that the device can reject frequency signals above the device’s 300 kHz bandwidth well.

picture2 OPA333,EMRR IN+ relationship with frequency

Compared to an external RC filter, an IC’s internal EMI filter has three benefits.Potential users can test the performance of amplifiers with integrated filters to ensure EMI suppression over a wide frequency range(2). Passive filter components are not ideal in terms of parasitic capacitance and inductance, which limit the filter’s ability to reject VHF noise. In contrast, the electrical characteristics of integrated circuits and on-chip passive components are well matched. Finally, ICs that use internal filters can bring other benefits to customers, such as lower component count, lower cost, and smaller board area.

To reduce the EMI susceptibility of a circuit, board designers should always take care to use good layout practices. This can be achieved by keeping trace lengths as short as possible, using surface mount components, and using printed circuit boards (PCBs) with dedicated signal return ground planes. Keep the ground plane intact as much as possible and keep digital signals away from the analog signal paths. Also, place RF bypass capacitors on all IC power pins. Keep these capacitors close to the device pins and ensure their impedance is as close to 0 ohms as possible at potential EMI frequencies.

references

· “How EMI Interferes with Circuits Through Dielectrics,” Baker, Bonnie, EDN 2/16/2012 pp. 18.

· “Op Amp EMI Rejection Ratio,” by Hall, Kuehl, August 2011, TI Application Report (SBOA128).

· “Specifications for EMI-Resistant Operational Amplifiers,” by Wagt, Staveren, January 15, 2011, in TI’s Application Note (SNOA497A).

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my country’s first 5G satellite communication test was successful, with a communication capacity of 10Gbps

According to Beijing Daily, my country’s first low-orbit broadband communication satellite with a communication capacity of 10Gbps launched a communication capacity test after 30 days in orbit.

　　

Galaxy Aerospace disclosed on February 19 that this 5G satellite verified the low-orbit Q/V/Ka frequency band communication capability for the first time in China, and achieved a successful communication test.

Chang Ming, the person in charge of the first satellite model of Galaxy Aerospace, introduced that for a month, the first satellite of Galaxy Aerospace has been in orbit in good condition. After the satellite enters orbit, the attitude maneuvering and mode switching are normal according to the flight program, and the onboard software, integrated electronics, and measurement and control systems are running normally. , and will continue to carry out communication performance tests in frequency bands such as Q/V/Ka.

It is reported that the satellite is the first satellite independently developed by my country’s commercial aerospace company Galaxy Aerospace, and also the first satellite of 200 kg in my country developed by a commercial aerospace company. A single satellite can cover 300,000 square kilometers, which is equivalent to about 50 Shanghai The area of ​​the city, the track height is 1200Km. Xu Ming, founder, chairman and CEO of Galaxy Aerospace, said that from the launch of the first satellite, Galaxy Aerospace will take the first step in the “space Internet”. In the future, Galaxy Aerospace will develop and produce low-cost, high-performance 5G satellites through large-scale research and development.

So, technically, how do ground personnel achieve satellite remote “physical examination”? To put it simply, this is to use the ground measurement and control station to track the satellite and conduct a “dialogue” with the satellite. Obtain the current working status of the satellite through “Heaven and Earth Dialogue”, such as working mode, orbit, attitude, temperature, equipment status, power consumption, etc. This is similar to the remote control desktop. These monitoring and control will conduct a series of inspections, maintenance or Troubleshoot.

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17-4 PH Stainless Steel Casting

17-4PH stainless steel is a precipitation hardened martensitic stainless steel. It is a combination of chromium, nickel, copper, and niobium that gives it a unique combination of properties. It is corrosion-resistant, strong, and easy to machine. It is also resistant to heat and stress-corrosion cracking. This makes it an ideal choice for castings when a combination of strength and corrosion resistance is needed.

17-4 PH Stainless Steel Composition
Type C Mn P Cr Ni Cu Nb
17-4 ph 0.07% 0.50% 0.04% 17% 4% 4% 0.50%

Why Choose 17-4 PH Stainless Steel

The high nickel and chromium content provide excellent corrosion resistance and strength. The addition of copper also increases the strength and hardness. It is also easily machinable and weldable.

  • High Strength & Corrosion Resistance
  • High Hardness & Tensile Strength
  • Excellent Fatigue Resistance
  • Good Weldability
  • Good Ductility & Formability
  • Easy to Machine

If you want to learn the difference between 17-4 PH and 304, you can read this article.

Process of 17-4 Stainless Steel Casting

17-4 PH stainless steel castings are produced using investment casting or sand casting processes. Investment casting is the preferred process due to its high accuracy and surface finish. The process involves pouring molten 17-4 PH stainless steel into a ceramic mold, which is then allowed to cool to form the casting. Sand casting is also used to produce 17-4 PH stainless steel castings, but it is not as accurate or as precise as investment casting.

  1. Make a 3D model to create a mold.
  2. Injecting wax into the mold to create wax models, examining and altering the designs if there are any issues.
  3. Assemble wax patterns into wax tree.
  4. Covering the wax with a ceramic glaze to form a shell.
  5. Heating the ceramic shell to remove the wax.
  6. Pouring in the melting shell.
  7. Breaking off the shell, and then employing shot blasters or conducting other surface treatments.

https://www.youtube.com/watch?v=1xcoO9KLfvA

SIPX Casting is very skilled at custom 17-4 ph stainless steel investment castings for a variety of applications, including oil & gas industry, food processing equipment, aerospace parts, chemical processing equipment, etc. As the top leading stainless steel casting manufacturer in China, our company can customize 17-4 ph stainless steel castings in different sizes and shapes.

 

 

Increase HEV/EV Traction Inverter Efficiency Using TI Functional Safety Gate Drivers

“As electric vehicle (EV) manufacturers race to develop lower-cost, longer-range models, Electronic engineers are under pressure to reduce traction Inverter power losses and improve system efficiency, which can extend driving range and gain competition in the market Advantage. Lower power loss results in higher efficiency, as it affects system thermal performance, which in turn affects system weight, size, and cost. As higher power levels of inverters are developed, the number of motors per vehicle increases, and trucks move towards pure electric power, there will continue to be a demand for lower system power losses.

“

As electric vehicle (EV) manufacturers race to develop lower-cost, longer-range models, electronic engineers are under pressure to reduce traction inverter power losses and improve system efficiency, which can extend driving range and gain competition in the market Advantage. Lower power loss results in higher efficiency, as it affects system thermal performance, which in turn affects system weight, size, and cost. As higher power levels of inverters are developed, the number of motors per vehicle increases, and trucks move towards pure electric power, there will continue to be a demand for lower system power losses.

In the past, traction inverters used insulated gate bipolar transistors (IGBTs). However, with advances in semiconductor technology, silicon carbide (SiC) metal-oxide-semiconductor field-effect transistors have higher switching frequencies than IGBTs, which not only improve efficiency by reducing resistance and switching losses, but also increase power and current density. Driving SiC in EV traction inverters, especially at power levels >100kW and using an 800V voltage bus, requires an isolated gate driver with reliable isolation technology, high drive capability, and fault monitoring and protection. .

Isolated Gate Drivers in Traction Inverter Systems

The isolated gate driver IC shown in Figure 1 is an integral part of the traction inverter power delivery solution. Gate drivers provide galvanic isolation from low voltage to high voltage (input to output), drive the high-side and low-side power stages of SiC or IGBT-based three-phase motor half-bridges, and enable monitoring and protection in the event of various faults.


Figure 1: EV Traction Inverter Block Diagram

Advantages of SiC Miller Platforms and High Strength Gate Drivers

For SiC, gate drivers must minimize turn-on and turn-off losses including turn-on and turn-off energy. MOSFET datasheets contain gate charge characteristics, and on the turn-on curve, there is a flat and horizontal area called the Miller plateau, as shown in Figure 2. The longer the MOSFET spends between on and off states, the more power is dissipated.


Figure 2: MOSFET turn-on characteristics and Miller plateau

When the SiC MOSFET switches, the gate-source voltage (VGS) through the gate-source threshold (VGSTH), clamped to the Miller plateau voltage (Vplt) remains the same because the charge and capacitance are fixed. For a MOSFET to switch, sufficient gate charge needs to be added or removed. Isolated gate drivers must drive the MOSFET gates with high currents to add or remove gate charge, thereby reducing power loss. The required SiC MOSFET charge that the isolated gate driver will add or remove is calculated by Equation 1, showing that the MOSFET gate current is proportional to the gate charge:

QGATE = IGATE ×tSW (1)

Among them, IGATEis the isolated gate driver IC current, tSWis the on-time of the MOSFET.

For traction inverter applications ≥150kW, the isolated gate driver should have >10A drive capability, which can switch SiC MOSFETs with high slew rates in the Miller plateau region while reaching higher switching frequencies. SiC MOSFETs have low reverse recovery charge (Qrr) and more stable on-resistance (RDS(on)) for higher switching speeds. The shorter the time the MOSFET stays in the Miller platform, the lower the power loss and self-heating.

TI’s UCC5870-Q1 and UCC5871-Q1 are high drive current, TI functional safety compliant 30A gate drivers with basic or reinforced isolation ratings and SPI serial peripherals for fault communication with microcontrollers Interface digital bus. Figure 3 compares SiC MOSFET turn-on between the UCC5870-Q1 and a competing gate driver. The UCC5870-Q1 gate driver has a peak current of 39A and maintains a current of 30A at the Miller platform with very fast turn-on. By comparing the blue V between the two driversGATEWaveform slope, it can also be clearly seen that its turn-on speed is faster. At a Miller platform voltage of 10V, the gate driver current of the UCC5870-Q1 is 30A, compared to 8A of the competing device.


Figure 3: Comparing TI’s isolated gate driver with competing devices in turning on SiC MOSFETs

Sources of Power Loss in Isolated Gate Drivers

A comparison of the gate driver Miller platform also involves switching losses in the gate driver, as shown in Figure 4. By comparison, the difference in switching losses of the drivers is as high as 0.6W. Switching losses are a significant part of the inverter’s overall power loss, so it is necessary to use high-current gate drivers.


Figure 4: Gate Driver Switching Losses vs. Switching Frequency

heat dissipation

Power losses can lead to higher temperatures, necessitating the use of external heat sinks or thicker printed circuit board (PCB) copper layers, further complicating system thermal management issues. The high drive force helps reduce the case temperature of the gate driver, thus eliminating the need for costly heat sinks or additional PCB ground planes to reduce the gate driver IC temperature. In the thermal image shown in Figure 5, the UCC5870-Q1 operates 15°C cooler due to its lower switching losses and higher drive current at the Miller platform.


Figure 5: Thermal dissipation of UCC5870-Q1 and competing gate drivers in driving SiC FETs

Epilogue

As EV traction inverters increase beyond 150kW, choosing an isolated gate driver with ultra-high drive capability in the Miller platform region can reduce power losses in SiC MOSFETs and enable faster switching frequencies, resulting in higher efficiency, Increase the driving range of new EV models. Meanwhile, TI’s functional safety compliant UCC5870-Q1 and UCC5871-Q1 30A gate drivers provide a number of design support tools to help simplify designs.

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Ex-engineer reveals that Sony kept a few secrets on PS5

Compared with Microsoft’s generous announcement of the technical parameters and appearance of the new generation of Xbox Series X (XSX for short), Sony is much more conservative on the PS5. The biggest highlight of PS5 performance is the ultra-fast SSD, but the CPU and GPU The specifications are not as good as the XSX host.

In addition, Microsoft has previously confirmed that the XSX console will support ray tracing and VRS variable frame rate technology, both of which are new technologies in the DX12 Ulimate specification. Sony officials are also secretive about these two technologies, but light chasing should not run.

As for VRS variable frame rate, former Sony engineer Matt Hargett explained why Sony has been reluctant to confirm VRS technology generously.

He said that VRS is a difficult technology to say. Whether it brings benefits or disadvantages depends on the game and depends on the game scene seen on the screen, so it is not as intuitive as technologies such as ray tracing or high resolution. come out.

That’s right, VRS is a new DX12 feature that allows developers to change the shading rate within a single frame, selectively reducing the level of detail in parts of the frame, including deep shadows, away from the camera, and outside of the player’s focus etc., improving performance with little noticeable impact on image quality.

VRS technology can improve performance and reduce image quality, which in turn can reduce performance and improve image quality, depending on how game developers choose.

In addition to the ambiguous attitude towards VRS, Matt Harget also said that Sony still has a lot of technology on the PS5 that has not been disclosed, which has aroused everyone’s interest. After all, the PS5 is currently worse than the XSX in terms of paper specifications, and continues to add mysteriously. Turn around.

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