There are many types of low noise power supplies: Linear Regulators

In Part 2 of this series, we will introduce low noise charge pump solutions. Charge pumps can provide a cost-effective power solution, but noise levels are typically in the hundreds or tens or millivolt range. Linear Technology’s innovative engineering design results in a charge pump solution with output rms noise below 5mV.

By: Kevin Scott

(In this three-part series, we’ll look at low-noise portable power supplies using different topologies. For many of these applications, using a low-noise linear In other applications (due to efficiency, power dissipation, or other constraints), low-noise solutions can also include charge-pump-based and Inductor-based DC/DC converters. Advances in circuit design combined with innovative design techniques have enabled Solutions that are too noisy cannot be used as low-noise alternatives.

Low Noise Linear Regulators

For portable systems requiring low output voltage noise, a linear regulator is often the “go-to” system power supply. Ideally, the linear regulator is powered directly from the battery supply instead of an intermediate DC/DC converter for lowest noise performance. Depending on the linear regulator, output voltage noise as low as 0.8µV rms is possible. For these applications, Linear Technology offers very low output noise devices such as the LT3042 and LT3045, 20V input, 0.8μV rms linear regulators with 200mA and 500mA capability, respectively.


Figure 1. LT3042 Low Noise Linear Regulator Block Diagram


Figure 2. LT3042 Integrated RMS Output Noise

Due to their unique current reference architecture, the LT3042 and LT3045 can be easily paralleled for higher output current and lower noise. Below is a low noise power supply using four LT3045s in parallel to achieve an output current of 3.3V and 2A. For every doubling of the number of devices used, the output noise is reduced by a factor of √2.


Figure 3. Paralleling LDOs increases current and reduces noise

While battery power is ideal from a noise standpoint, it is often not ideal when efficiency and system run time are considered. More commonly, systems use DC/DC conversion for more efficient power conversion. In these cases, the lowest noise solution can be achieved with a switching regulator followed by a post-regulated linear regulator, which has low output voltage noise and high power supply ripple rejection (PSRR); a high PSRR specification is required because A linear regulator must be able to adequately reject the switching noise of the DC/DC converter; now that switching regulators have frequency ranges up to 4MHz, this is no small feat. These high frequencies exceed the control loop bandwidth of the linear regulator, so the PSRR is not determined by the IC but by the parasitics of the device. Not coincidentally, the LT3042 and LT3045 also have excellent PSRR of >2dB beyond 75MHz and >10dB beyond 50MHz. This enables them to substantially reduce switching frequency noise over a wide frequency range while providing the system with minimal additional output noise.


Figure 4. LT3045 Power Supply Ripple Rejection

If the customer is looking for the best noise performance, the choice is easy. But often the term “low noise” is more qualitative; power supply noise needs to be low enough so as not to adversely affect the measurement performance and accuracy of the system. For these applications, low noise can be defined by RMS values ​​from microvolts to millivolts.

In Part 2 of this series, we will introduce low noise charge pump solutions. Charge pumps can provide a cost-effective power solution, but noise levels are typically in the hundreds or tens or millivolt range. Linear Technology’s innovative engineering design results in a charge pump solution with output rms noise below 5mV.

The Links:   CM900HC-90H 6MBI150U4B-120-50 IGBTS

M4/3 cannon Olympus 150-400mm lens real photo

This article is from Hummingbird.com

As early as January 2019, Olympus announced that it would develop a lens model named M.ZUIKO DIGITAL ED 150-400mm F4.5 TC1.25X IS PRO, which has a focal length equivalent to 35mm of 300-800mm , and comes with a 1.25× teleconverter, which is especially suitable for shooting wild animals, sports and other subjects. At that time, the lens roadmap displayed by Olympus showed that this lens will be officially unveiled in 2020, that is, this year. Recently, foreign media have shown photos of this lens on the street.

Olympus ED 150-400mm f/4.5 TC1.25X IS PRO

The Olympus ED 150-400mm f/4.5 TC1.25X IS PRO lens has a built-in 1.25X teleconverter, which is equivalent to the 300-800mm f/9 of the 135 frame. At the same time, after the 1.25X teleconverter is turned on, the The lens is actually equivalent to 375-1000mm f/11. On this basis, you can also choose the new 2X teleconverter MC-20 to achieve an equivalent focal length of 600-1600mm f/18, and the equivalent focal length after turning on the 1.25X built-in teleconverter It is 750-2000mm f/22. This lens is designed to be dustproof and waterproof, and can work normally in the low temperature environment of -10°C.

·Editor’s point of view

This 150-400/4.5 PRO is a very good super telephoto zoom lens with a built-in extender, which can directly shoot farther pictures without changing the lens, and the original lens is equivalent to a focal length of 300-800mm It has been able to meet the telephoto needs of most users. With Auba’s 7.5+ anti-shake, handheld telephoto is not a dream.

The Links:   CM200RXL1-12A CM600DX-24T IGBTMODULE

Renesas RX62T Motor Control Solution (YMCRPRX62T)

The RX62T of Renesas uses a 100-MHz 32-bit RX MCU, the operating frequency is up to 100MHz, and the performance is 165DMIPS at 100MHz. It has single-precision 32-bit IEEE-754 floating point, and the accumulator can process 64-bit results from 32×32-bit operations. , The multiplication and division unit can handle 32×32-bit operations, with fast interrupt function, integrated 12-bit ADC, 100MHz PWM, working voltage 3.3V or 5V, mainly used in household appliances, industrial automation, office equipment, audio equipment and consumer Class Electronic products, etc. This article introduces the RX62T series main features, block diagram, performance and function of the RX62T motor control evaluation kit, technical characteristics and complete circuit diagram.

Main features of RX62T series:

■ 32-bit RX CPU core

 Max. operating frequency: 100 MHz Capable of 165 DMIPS in operation at 100 MHz

 Single precision 32-bit IEEE-754 floating point

 Accumulator handles 64-bit results (for a single instruction) from 32- × 32-bit operations

 Multiplication and division unit handles 32- × 32-bit operations (multiplication instructions take one CPU clock cycle)

 Fast interrupt

 Divider (fastest instruction execution takes two CPU clock cycles)

 Fast interrupt

 CISC Harvard architecture with 5-stage pipeline

 Variable-length instructions: Ultra-compact code

 Background JTAG debugging plus high-speed tracing

■ Operating voltage

 Single 3.3- or 5-V supply; 5-V analog supply is possible with 3.3-V products

■ Low-power design and architecture

 Four low-power modes

■ On-chip main flash memory, no wait states

 100-MHz operation, 10-ns read cycle

 No wait states for reading at full CPU speed

 64-Kbyte/128-Kbyte/256-Kbyte capacities

 For instructions and operands

 User code programmable via the SCI or JTAG

■ On-chip data flash memory

 Max. 32 Kbytes, reprogrammable up to 30,000 times

 Erasing and programming impose no load on the CPU.

■ On-chip SRAM, no wait states

 8-Kbyte/16-Kbyte SRAM

 For instructions and operands

■ DMA

 DTC: The single unit is capable of transfer on multiple channels

■ Reset and supply management

 Power-on reset (POR)

 Low voltage detection (LVD) with voltage settings

■ Clock functions

 External crystal oscillator or internal PLL for operation at 8 to 12.5 MHz

 Internal 125-kHz LOCO for the IWDT

 Detection of main oscillator stoppage (for IEC 60730 compliance)

■ Independent watchdog timer (for IEC60730compliance)

 125-kHz LOCO clock operation

Software is incapable of stopping the robust WDT.

■ Up to 7 communications interfaces

 1: CAN (compliant with ISO11898-1), incorporating 32 mailboxes

 3: SCIs, with asynchronous mode (incorporating noise cancellation), clock-synchronous mode, and smart-card interface mode

 1: I2C bus interface, capable of SMBus operation

 1: RSPI

 1: LIN

■ Up to 16 16-bit timers

 8: 16-bit MTU3: 100-MHz operation, input capture, output compare, two three-phase complementary PWM output channels, complementary PWM imposing no load on the CPU, phase-counting mode

 4: 16-bit GPT: 100-MHz operation, input capture, output compare, four complementary single-phase PWM output channels, or one three-phase complementary PWM output channel and one single-phase complementary PWM output channel, complet Mental PWM imposing no load on the CPU, operation linked with comparator (for counting and control of PWM-signal negation), detection of abnormal oscillation frequencies (for IEC 60730 compliance)

 4: 16-bit CMT

■ Three A/D converter units for 1-MHz operation, for a total of 20 channels

 Three units are capable of simultaneous sampling on seven channels

 Self diagnosis (for IEC60730 compliance)

 8: Two 12-bit ADC units: three sample-and-hold circuits, double data registers, amplifier, comparator

 12: Single 10-bit ADC unit

■ CRC (cyclic redundancy check) calculation unit

 Monitoring of data being transferred (for IEC 60730 compliance)

 Monitoring of data in memory (for IEC 60730 compliance)

■ Up to 61 input–output ports and up to 21 input-only ports

 PORT registers: Monitoring of output ports (for IEC 60730 compliance)

■ Operating temp. range

 –40C to +85C

Figure 1. RX62T Series Block Diagram

RX62T Motor Control Evaluation Kit

Ready-to-use Platform for Evaluating Sensorless Vector Control and Position Control With the Renesas RX600 Motor Control Evaluation Kit, you can:

■■ Learn the RX62T motor control feature set

■■ Explore advanced motor control algorithms

■■Monitor speed and position regulation

■■Observe responsiveness to load changes

■■Connect with user-supplied inverter

■■ Debug using on-board test points and the E1 emulator User-friendly GUI for Performance Evaluation

■■ Speed, voltage and current tracking

■■ Bi-directional speed/position control

■■User selectable vector control algorithms

■■ System status indicator

■■ Data-logging

Kit also offers:

■■ Sensorless vector control (1 or 3 shunt)

■■ External or internal PGA selection (via jumpers)

■■ Position control using encoder

■■ Standalone mode using LCD and push-button

■■ Connector for user-supplied inverter stage

Use the Renesas RX600 Motor Control Evaluation Kit to develop your motor control solutions. With its high-performance CPU and FPU capability, and advanced analog and timer peripherals, the RX62T is an ideal MCU for inverter and motor control applications. The RX62T firmware supports many kinds of motor control, including high-precision three-phase sensorless vector control. The supplied GUI provides precise tracking of speed, position, voltage and current.

The RX62T Motor Control Kit is an evaluation tool for Renesas microcontrollers and incorporates the following features:

• Single board that consists of MCU and inverter stage

• Capability to drive two motors:

24V up to 5A 3-phase Brushless DC motor with hall sensors, encoder and sensor-less with on-board hardware

Any 3-phase Brushless DC or AC Induction motor with user-supplied power stage

• Support for dual operation mode:

GUI mode : controlled by GUI from a personal computer through USB connection Standalone mode: controlled by on-board potentiometer, pushbuttons and LCD

• Ease-of-use:

User code debugging

User interface such as: switches, potentiometer, LED, LCD

Sample application code

Sample peripheral initialization code

• Multiple sensor and sensor-less motor control algorithms

Three-shunt and single-shunt current measurement support

External amplifier and internal PGA support

• On-board USB isolator for E1 emulator

RX62T Motor Control Evaluation Kit Applications:

Home appliances, industrial automation, office equipment, audio equipment, consumer products etc.

The RX62T Motor Control Evaluation Kit includes:

–Control Board with RX62T MCU and RJK0656DPB Power MOSFETs

–24V/4-pole BLDC motor with encoder and hall sensor

–E1 debugger for software debugging and Flash programming

–CD ROM containing sample code, motor control library, HEW IDE and evaluation copy of Renesas RX compiler, schematics, user guide and application notes


Figure 2. RX62T Motor Control Evaluation Kit Outline Drawing

RX62T Motor Control Evaluation Kit Technical Features:






Figure 3. RX62T Motor Control Evaluation Kit Circuit Diagram(1)

Figure 4. RX62T Motor Control Evaluation Kit Circuit Diagram (2)

Figure 5. RX62T Motor Control Evaluation Kit Circuit Diagram(3)

Figure 6. RX62T Motor Control Evaluation Kit Circuit Diagram(4)

Figure 7. RX62T Motor Control Evaluation Kit Circuit Diagram(5)

Figure 8. RX62T Motor Control Evaluation Kit Circuit Diagram (6)

Figure 9. RX62T Motor Control Evaluation Kit Circuit Diagram(7)

Figure 10. RX62T Motor Control Evaluation Kit Circuit Diagram(8)

Figure 11. RX62T Motor Control Evaluation Kit Circuit Diagram(9)

Figure 12. RX62T Motor Control Evaluation Kit Circuit Diagram(10)

Figure 13. RX62T Motor Control Evaluation Kit Circuit Diagram(11)

Figure 14. RX62T Motor Control Evaluation Kit Circuit Diagram(12)

Figure 15. RX62T Motor Control Evaluation Kit Circuit Diagram(13)

Figure 16. RX62T Motor Control Evaluation Kit Circuit Diagram(14)

Figure 17. RX62T Motor Control Evaluation Kit Circuit Diagram(15)

Figure 18. RX62T Motor Control Evaluation Kit Circuit Diagram(16)

Figure 19. RX62T Motor Control Evaluation Kit Circuit Diagram(17)

Figure 20. RX62T Motor Control Evaluation Kit Circuit Diagram(18)
For details, see:
http://documentation.renesas.com/doc/products/mpumcu/doc/rx_family/r01ds0096ej_rx62t.pdf
and
http://am.renesas.com/media/applications/key_technology/motor_control/reference/rx/YMCRPRX62T_User_Manual.pdf

as well as
http://am.renesas.com/media/applications/key_technology/motor_control/reference/rx/YMCRPRX62T_Schematic.pdf

The Links:   1MBI600LN-060A 7MBI75N-060 BEST-igbt

Israeli government investigates NSO Group office

According to the Israeli Ministry of Defense, various agencies of the Israeli government visited the offices of NSO Group to investigate the security company’s sale of spyware to attackers.

The Defense Department announced the operation in a tweet on Wednesday, but did not say which government agencies were involved. Briefly, Israeli agents raided NSO Group’s offices in Herzliya, near the city of Tel Aviv, according to a post on The Record by analytics firm Recorded Future.

“Representatives of several government agencies visited NSO today to examine the company’s publications and conduct a detailed investigation of the matter,” the Defense Department said on Twitter.

The company told the Record that NSO Group is cooperating with the authorities in full transparency.

According to the company’s statement in the post: “We believe that this inspection will prove that the facts are the same as the company has always stated to the outside world, and we oppose the recent false allegations made against us by the media.”

However, security experts and industry watchers aren’t so sure about the company’s claims on the matter.

Author, journalist and activist Cory Doctorow tweeted: “NSO insists that this report is false, but also insists there is nothing wrong with spying on people, arguing that if they are not allowed to help rulers find kidnappings, imprisonments and The terrorists will murder us all.”

public investigation

According to Israeli news outlet Calcalist, the Israeli government’s investigation is aimed at uncovering a report called “Project Pegasus” that reviewed data leaked by NSO Group and sparked a burgeoning international incident .

The British “Guardian” report disclosed that the company has stored more than 50,000 mobile phone numbers worldwide, and claimed that Pegasus malware is currently widely used to target social activists, journalists, business executives and politicians. Attack, the software used various vulnerabilities, including a zero-day vulnerability in Apple’s iOS system.

Seventeen media organizations are currently involved in the investigation, which also accuses NSO Group of selling Pegasus to a third-party government agency. These groups would use it to hack the phones of dissident politicians and others who might be critical of politics.

The malware can covertly and remotely control the phone to monitor user activity, allowing the operator to even read encrypted messages sent by victims via Signal and Telegram.

The report sparked a global pushback against the NSO attack, with the international human rights group calling the mass abuses committed through covert online surveillance the new global human rights crisis.

Security experts also weighed in, including Paul Bischoff, a privacy advocate at Comparitech, who called NSO an arms dealer. Others, such as Pegasus, exploited iOS zero-day vulnerabilities while also pointing the finger at Apple’s proprietary security ecosystem.

Still, while many have criticized NSO Group’s campaign, some see the report and subsequent investigation as an attempt to damage the reputation of the Israeli cyber industry at a time when Israel is under international fire for its ongoing military campaign against the State of Palestine. widely criticized.

A user @IntelMA, who claims to be North and West African Military Intelligence, tweeted: “They are trying to damage the reputation of the Israeli cyber industry, NSO won’t be the first and won’t be the last, they have their plots, We know that in our hearts.”

The Links:   G156HAN01.0 NL8060BC31-32

Application-oriented hybrid stepper motor technology greatly improves the dynamic torque of the motor

[Introduction]Stepper motors are one of the most challenging motors today. They have high-precision steps, high resolution and smooth motion. Stepper motors generally need to be customized to achieve the best performance in specific applications. Often custom design attributes such as stator winding patterns, shaft configurations, custom housings, and specialized bearings make the design and manufacture of stepper motors extremely challenging.

Motors can be designed to fit the application, rather than forcing the application to fit the motor, flexible motor design can take up minimal space. Miniature stepper motors are difficult to design and manufacture and often cannot compete with larger motors. Miniature stepper motors provide a unique design approach. With the advent of hybrid stepper motor technology, miniature motors are beginning to be used in medical equipment and laboratories In the field of automation, especially applications requiring high precision, such as micropumps, fluid metering and control, pinch valves and optical sensor control. Miniature stepper motors can even be incorporated into electric hand tools, such as Electronic pipettes, where integration of hybrid stepper motors was previously impossible.

Miniaturization is an ongoing concern in many industries and one of the main trends in recent years. For production, testing or everyday laboratory use, motion and positioning systems require smaller and more powerful motors. The motor industry has been designing and manufacturing small stepper motors for a long time, and motors small enough for many applications still don’t exist. Where motors are small enough, they lack the specifications required for the application, such as delivering high enough torque or speed to be competitive in the marketplace. The sad option is to use a big frame stepper motor and shrink all other components around, often via special brackets and additional hardware for mounting. Motion control in this small area is extremely challenging, forcing engineers to make compromises in the spatial structure of the device.

Standard brushless DC motors are structurally and mechanically self-supporting. The rotor is suspended inside the stator by end caps at both ends. Any peripherals that need to be connected are usually bolted to the end caps. The end caps easily occupy the to 50% of the total length of the motor. Frameless motors reduce waste and redundancy by not requiring additional mounting brackets, plates or brackets, and all structural and mechanical support required by the design can be integrated directly inside the motor. The benefit of this is that the stator and rotor can be seamlessly integrated into the system, reducing size without sacrificing performance.

Miniaturization of stepper motors is challenging. The performance of the motor is directly related to its size. As the frame size decreases, so does the space for rotor magnets and windings. This affects not only the maximum torque output available, but also It will affect the running speed of the motor. Attempts to make a NEMA6 size hybrid stepper motor in the past have mostly failed, thus indicating that the NEMA6 frame size is too small to provide any useful performance. By applying experience in custom design and expertise in several disciplines, the motor industry was able to successfully create a hybrid stepper motor technology that had failed elsewhere, a NEMA Type 6 stepper motor that not only delivers massive available dynamic torque, but also offers a high level of precision.

A typical permanent magnet motor has 20 steps per revolution, which is a step angle of 18 degrees. Compared with a 3.46 degree motor, it can provide 5.7 times the resolution. This higher resolution directly translates into higher accuracy, providing a Hybrid stepper motors. Coupled with this step angle variation, low inertia rotor design, the motor is able to achieve over 28 grams of dynamic torque at nearly 8000 rpm, providing speed performance similar to standard brushless DC motors. Increasing the step angle from the typical 1.8 degrees to 3.46 degrees allows them to achieve nearly double the holding torque of the closest competing design, at up to 56 g/in, nearly the same holding torque for the same size (up to 14 g/in) four times that of conventional permanent magnet stepper motors.

in conclusion

Micro stepper motors can be used in various industries that require a compact structure while maintaining a high level of precision, especially in the medical industry, from the emergency room to the patient’s bedside, to laboratory equipment, micro stepper motors are more cost-effective high. There is currently a lot of interest in handheld pipettes, the tiny stepper motors provide the high resolution needed to precisely dispense chemicals, these motors offer higher torque and higher quality. For labs, tiny stepper motors become the benchmark for quality. The compact size makes miniature stepper motors the perfect solution, whether it is a robotic arm or a simple XYZ stage, stepper motors are easy to interface and can provide open or closed loop functionality.

The Links:   P080A2206 BSM150GT120DN2(6)

The CITE2023 series of high-end forums is coming, focusing strongly on China’s electronic information industry

[Introduction]The 11th China Electronic Information Expo (CITE2023) will be held at the Shenzhen Convention and Exhibition Center from April 7 to 9, 2023. As a national platform for displaying the latest products and technologies of the global electronic information industry, CITE has become the electronic information expo with the largest scale, the most complete industrial chain, the most abundant activities and the fastest growing influence in Asia. An influential annual event in the electronic information industry.

The 11th China Electronic Information Expo (CITE2023) will be held at the Shenzhen Convention and Exhibition Center from April 7th to 9th, 2023. As a national platform for displaying the latest products and technologies of the global electronic information industry, CITE has become the electronic information expo with the largest scale, the most complete industrial chain, the most abundant activities and the fastest growing influence in Asia. An influential annual event in the electronic information industry.

As an important part of the expo, this expo will innovate and optimize the launch of the “1+1+7+N” activity square, hold “1” opening summit of China Electronic Information Expo, and “1” innovative products of the new generation of information technology industry Selection activities, “7” professional key field activities and “N” parallel industry forum activities.

It is worth paying attention to the seven major industry forums, which focus on key areas of concern in the industry, including “industrial digitalization, 5G, Display industry, Internet of Vehicles, Xinchuang, electronic components, and big data storage.” The above forums will bring together experts, scholars, and practitioners from various industries to discuss and exchange the latest technologies and market trends, and provide development directions and ideas for the development of China’s electronic information industry.

1. Industrial digitalization activities

The digital economy is becoming a key force in reshaping the global economic structure and changing the global competitive landscape. Industrial digitalization mainly refers to the extensive application of data and digital technology in the production process of the real economy, while industrial intelligence is the process of gradually replacing people with artificial intelligence on the basis of it, not only in physical labor, but more importantly, in mental work. Industrial digitalization is the foundation of industrial intelligence, and sufficient digitalization is the prerequisite for the realization of intelligence. The specific direction of digitization includes data collection and analysis, digitization of production process, digitization of product design, digitization of supply chain, digitization of service, etc. In the future, industries including smart cars, smart homes, smart home appliances, smart buildings, smart healthcare, smart elderly care, and smart education will undergo digital transformation and upgrading through information technology to reduce costs and increase efficiency.

The main forums of this industrial digitalization event are the “Innovation and Development Forum of Advanced Manufacturing Industry Clusters” and “2023 China Digital Human Conference”. During the meeting, the guests will conduct in-depth discussions on the current hot issues in the information and communication industry. Forum members have rich academic and industry experience. Through exchanges and cooperation, they promote the innovation and development of information and communication technologies, and promote the prosperity and development of the information and communication industry.

2. 5G Industry Series Activities

With the continuous development of a new round of technological revolution, the global economic structure is facing reshaping, giving birth to the digital transformation of the manufacturing industry. The Industrial Internet is becoming an innovation path, and AIoT, as an important carrier, has become an important channel for the digitalization and intelligent upgrading of traditional industries, and it is also an important direction for the development of the Internet of Things. At present, the AIoT industry is in an important stage of transition from the industrial accumulation period to the industrial growth period, and is redefining the new future of intelligent interconnection of all things. According to GSMA research, by 2030, the annual 5G upgrade will contribute more than US$600 billion to the global economy, which is about 2.1% of the expected revenue growth in all industries and fields in the next 10 years. Among them, 5G efficiency will be concentrated in the manufacturing, service and retail industries, and the contribution of these industries will account for nearly one-third of the 600 billion US dollars.

In recent years, China’s 5G AIoT industry has developed rapidly. On the one hand, the mature promotion of 5G network provides faster, more reliable and safer data transmission for the AIoT industry, and accelerates the development of 5G AIoT. On the other hand, the intelligence of IoT devices will make devices more intelligent and interconnected, providing more application scenarios for the AIoT industry. In addition, AI technology will also be more widely used in smart home, smart city, smart medical care, smart driving and other fields, and more widely empower 5G AIoT applications. At the same time, the explosive growth of related 5G applications has also made data security and privacy protection more and more important. In this context, the development of the 5G AIoT industry requires the participation of enterprises in all links of the industrial chain, building an ecosystem through cooperation, and strengthening technological innovation and industrial cooperation.

The main forum of this series of 5G industry activities includes the “China (Great Bay Area) Industrial Internet Development and Security Summit”. Experts and business leaders from all walks of life will focus on issues such as the status quo, trends, application practices, technological innovation, and security of the Industrial Internet. Through government-industry-university-research cooperation and exchanges, activities such as discussing cutting-edge technologies, policy interpretation, and case sharing for the digital transformation of the manufacturing industry will accelerate the development of the industrial Internet and achieve the goal of manufacturing a powerful country.

3. Display industry series activities

As the main carrier of information presentation in the digital age and the basic window of human-computer interaction, my country’s new display industry has continued to “accelerate” and reach a “new level” in recent years. The annual production capacity of display panels has reached 200 million square meters, and the industry scale ranks first in the world, becoming an important force for upgrading information consumption and expanding the digital economy. In terms of key core technologies, my country’s display industry continues to break through technical barriers. In the field of liquid crystal displays, domestic companies have achieved leadership and have formed leading competitiveness in terms of technology, products, market share, cost, and efficiency. The global market share exceeds 70%. . In the field of organic light-emitting diodes, domestic enterprises have mastered the core technology, and expanded into technological innovation fields such as high refresh rate and pixel arrangement, and the production scale has rapidly expanded. In terms of new-generation display technologies such as micro-display, printed display, and laser display, my country is catching up, and breakthroughs in technology and industrial chains are imminent.

Over the years, the rapid development of the display industry has effectively empowered multiple industries such as smartphones, TVs, monitors, notebook computers, and tablet computers, and has been used in many emerging industries such as digital cultural tourism, digital medical care, education and training, automotive displays, and digital equipment. unique role in the industry. In addition, the display industry also provides the material basis and realization path for forward-looking industries such as metaverse and digital twins.

The display industry series event forums include “2023 China International Display Industry Leaders Summit”, “2023 China Metaverse Ecological Development Conference”, “2023 China International Mini/Micro-LED Industry Summit”, and “2023 Pearl River Delta Third Generation semiconductor Industrial Technology Summit”. The forum will invite global semiconductor and display industry leaders to discuss new development opportunities for the display industry.

4. Smart car series activities

As the automobile industry enters the era of “electrification, intelligence, networking, and sharing”, the traditional automobile industry chain is undergoing major changes. Emerging functions and technologies such as autonomous driving, smart cockpit, and Internet of Vehicles have begun to empower the traditional automobile industry and reshape the value chain.

In recent years, the state has successively issued policies such as “Smart Vehicle Innovation and Development Strategy” and “Intelligent Networked Vehicle Technology Roadmap 2.0” to guide and standardize the development of the domestic intelligent networked industry from the top-level design, and accelerate the implementation of my country’s smart vehicle strategy. The automotive industry will focus on the development of networking and intelligence, and plan to gradually shift from single-vehicle intelligence to multi-vehicle collaboration, as well as the coordinated development of “smart cars” and “smart roads”, and build a supportive “vehicle-road-network-cloud-map “An integrated intelligent networked vehicle communication environment, avoiding various security risks such as networks, data, and industries, and finally realizing high-level autonomous driving, all of which put forward new development requirements for technological innovation and product R&D innovation. In addition, the smart cockpit makes the car transform from a “single means of transportation” to a “third space”. Faced with the emergence of a large number of personalized needs and innovations and the rapid iterative development of smart cockpit technology, its industrial chain will continue to extend, and around “ecological collaboration” and “cross-border extension”, more businesses will enter this big ecology and jointly serve consumption. provide more value-added services.

During this exhibition, the Internet of Vehicles forums mainly include “2023 Intelligent Networking and Autonomous Driving Innovation Technology Forum” and “Original Plant Purchasing Matchmaking Meeting”. The forum will invite the upstream and downstream of the industry chain, including vehicle manufacturers, smart chips, vehicle displays, smart voice, Internet of Vehicles companies, and big data companies, to discuss new trends in the development of the automotive industry.

5. Xinchuang series of activities

Information technology application innovation industry (xinchuang industry) includes basic hardware, basic software, application software, information security and other fields. It is an important part of “new infrastructure” and an important guarantee for promoting the digital transformation of my country’s economy. The core of the development of Xinchuang industry is to build the underlying architecture system of localized information technology software and hardware and the full life cycle ecosystem through industry applications, solve the problem of “stuck necks” in key links of core technologies, and lay a digital foundation for China’s future development. During the “14th Five-Year Plan” period, as my country strengthens the innovative application of key technologies, focuses on key areas such as high-end chips, operating systems, key algorithms for artificial intelligence, and sensors, and accelerates research and development breakthroughs and iterative applications of basic theories, basic algorithms, and equipment materials, The information technology application innovation industry is ushering in a new round of growth curve and entering a golden period of high-speed development.

The “Third Information Technology Application Innovation Industry Forum” held during this exhibition will focus on the Xinchuang industry, with the theme of “Rising Great Powers, Xinchuang Road Ahead”, relying on the industry’s advanced technology and products, with new For the purpose of product release and new technology demonstration, focus on new developments, new achievements and new experience in the fields of localized infrastructure, basic software, information security, application software and cloud services. The forum will invite many well-known companies in the Xinchuang industry chain, as well as experts and scholars, to conduct multi-dimensional exploration and sharing around “Xinchuang” to help the Xinchuang industry go deeper.

6. Electronic components series activities

Electronic components are the cornerstone supporting the development of the information technology industry and the key to ensuring the safety and stability of the industrial chain supply chain. They are widely used in smart terminals, automotive electronics, 5G communications, Internet of Things, aerospace, energy transportation, military equipment and other fields. Quality, level and reliability directly determine the performance of electronic systems and complete machine products.

In recent years, China has become the world’s largest producer of electronic components, and the electronic component industry is booming in both production and sales, with an industry scale exceeding 2 trillion yuan. Under the guidance of policies, the industry is accelerating the process of building a self-reliant and self-reliant basic electronic ecology. At the same time, the pace of localization has been accelerated, and the level of independent guarantee has been significantly improved. Even so, my country’s electronic components industry is still facing development bottlenecks, and is still under the control of others in terms of core technology, facing the threat of being stuck. In this context, in addition to increasing research and development efforts to overcome difficulties, China’s electronic components industry also needs to focus on supply chain, marketing channels, business environment and other aspects to enhance the flexibility and resilience of the supply chain.

The series of component activities held during the exhibition mainly include “The 5th Special Electronic Components Independent Innovation Development Forum and China Ordnance Industry Group Supplier Conference”, “2023 CITE Electronic Components Innovation and Supply Chain Security Development Summit”, “2023 China Semiconductor Manufacturing Supply Chain Localization Development Conference”, “2023 Industrial Control MCU Technology and Application Innovation Forum”, “Semiconductor and Advanced Computing Forum”, “Electronic Manufacturing Alliance PCBA Design Competition” and other related forums. The forum will focus on the distribution supply chain of electronic components, and empower China’s manufacturing industry to achieve a safe and reliable supply chain of electronic components. At the same time, it will gather industry authorities, market leaders, technical experts, and purchasing elites to answer questions and share solutions for the audience, provide a display and trading platform for enterprises, and promote the localization of the semiconductor industry to become bigger and stronger.

7. Big data storage series activities

In recent years, with the proliferation of IoT devices, the amount of data worldwide has grown exponentially. According to IDC’s forecast, the total amount of global data will reach 175ZB by 2025. These high-value, large-volume, fast-speed, and diverse big data also face problems such as the transmission, indexing, and management of massive small files, the segmentation and storage of massive large files, and the scalability and reliability of storage systems. . With the explosive growth of big data services such as 5G, AI, Internet of Things, and cloud computing, relying on traditional data storage and processing tools has been unable to meet the characteristics and requirements of “large scale, multiple types, and fast new growth”. New technologies and products to support storage and computing, in order to achieve more efficient and safer industry needs.

During the exhibition, “2023 Shenzhen International Big Data and Storage Summit”, “2023 Shenzhen International Data Center Conference”, “2023 Shenzhen Privacy Computing Summit” and “GAI and Computing Chip Seminar” will focus on the storage industry and cloud computing and many other hot technology fields, attracting representatives and experts from outstanding enterprises in the upstream and downstream industries of storage to participate in the exchange.

Write at the end:

CITE is Asia’s largest electronic information expo with the most complete industrial chain and the most abundant activities. With the latest changes and innovations, let us look forward to this grand exhibition and explore the excitement of the digital future together.

Concurrent activities of the 11th China Electronic Information Expo

forum name

CITE2023 Opening Forum

1

China Electronic Information Expo Opening Forum

2

Opening Ceremony of 2023 Special Electronic Components Supply and Demand Matching Event

CITE2023 Innovation Awards

3

China Electronic Information Expo Gold Award

4

China Electronic Information Expo Innovation Award

CITE2023 Industrial Digitalization Activities

5

Advanced Manufacturing Industry Cluster Innovation Development Forum
And the unveiling ceremony of Shenzhen Excellent Engineer Collaborative Innovation Center

6

2023 China Digital Human Conference

7

Difficulties and Countermeasures of Manufacturing Digital Transformation Closed-door Seminar

CITE2023 5G Industry Series Activities

8

China (Great Bay Area) Industrial Internet Development and Security Summit

CITE2023 International Display Series Activities

9

2023 China International Display Industry Leaders Summit

10

2023 China Metaverse Ecological Development Conference

11

2023 Pearl River Delta Third Generation Semiconductor Industry Technology Summit

12

2023 China International Mini/Micro-LED Industry
Technology Summit

13

Symposium on Innovation and Development of LED and Application Industry

CITE2023 Smart Car Series Activities

14

2023 Electronic Industry Logistics and Supply Chain Development Forum
And the first preparatory meeting of the Electronic Industry Supply Chain Branch of the China Federation of Things

15

2023 Intelligent Connectivity and Autonomous Driving Innovation Technology Forum

16

Procurement matchmaking meeting for OEMs

CITE2023 Xinchuang Series Activities

17

The 3rd Information Technology Application Innovation Industry Forum

CITE2023 Electronic Components Series Activities

18

The 5th Special Electronic Components Independent Innovation Development Forum and China Ordnance Industry Group Supplier Conference

19

China Shipbuilding Group Electronic Components Framework Agreement Procurement Platform Promotion Conference

20

2023 CITE Electronic Components Innovation and Supply Chain Security Development Summit

twenty one

2023 China Semiconductor Manufacturing Supply Chain Localization Development Conference

twenty two

2023 Industrial Control MCU Technology and Application Innovation Forum

twenty three

The 5th China Chip Application Innovation Technology Symposium

twenty four

Semiconductor and Advanced Computing Forum

25

Electronics Manufacturing AlliancePCBA Design Contest

CITE2023 Big Data Storage Series Activities


The Links:   G121X1-L03 DMF50260NFU-FW TFT-LCD

Application of NAND FLASH in Storage Test System

Summary:It mainly introduces Samsung’s NAND FIJASH memory K9K8G08UOM, FPGA as the core module to control the read operation, write operation and erase operation of K9K8G08UOM, and the specific connection method of FLASH memory in hardware design. The correctness of its function has been verified by actual circuit measurement.

Key words:NAND FLASH: K9K8G08UOM: FPGA: read operation

0 Preface

With the rapid development of computer technology, the storage system capacity has changed from a few KB storage space in the past to the current T8; even PB storage space will be achieved in the near future, and its data access capabilities are expanding rapidly. The new fields such as SCSI, FC, SAN, iSCSI, IPStorage, and data life cycle management that followed have given vigorous vitality to computer technology and network technology. The improvement of data storage performance is usually accomplished by adding more physical disk drives to the infrastructure or using faster disk drives.

Airborne storage devices require high reliability, high impact resistance, shock resistance, moisture resistance, high pressure resistance and high temperature resistance, while disk drives have mechanical rotation when accessing data, and their impact resistance and vibration resistance are not strong, so they are not Suitable for use in harsh environments such as aerospace. The emergence of solid-state memory (SSD) based on semiconductor memory chip flash memory” title=”flash memory”>flash memory has solved the above problems. As a storage medium, SSD has no mechanical rotating parts, high storage density, high reliability, small size, It is light in weight, anti-vibration, anti-shock, wide temperature range, strong environmental adaptability, and can meet the data storage requirements under harsh conditions. Therefore, high-performance and large-capacity solid-state memory has become the only data in major military projects. storage method.

1 NAND FLASH Memory control requirements

1.1 NAND FLASI-1 memory structure and function introduction

We choose Samsung’s K9K8G08UOM FLASH chip as the medium of the storage system. The storage capacity of this NAND F1ash is 8448Mbit, of which the main data area is 8192Mbit, the auxiliary data area is 256Mbit, and the working voltage is 2.7V~3.6V , The width of the I/O port is 8 bits. NAND FLASH is different from NOR FLASH. NOR FLASH does not allow bad blocks in the chip when it leaves the factory, but NAND FLASH allows bad blocks in the finished product. This is a unique phenomenon of NAND technology.

The 8448M bit memory in the chip is organized according to the concept of block and page. A FLASH memory contains 8192 blocks (block), each block contains 64 pages (page), and each page has 2112 Bytes. The chip has a data register with a capacity of 2112 Bytes, called the page register, which is used as a buffer during data access. When reading and writing a certain page in the chip, its data is first transferred to this data register Inside, exchange data with the outside of the chip through the data buffer to complete the read and write functions. The 2112Bytes in the page are divided into a main data area of ​​2048 Bytes and an auxiliary data area of ​​164 Bytes. The main data area stores user data, and the auxiliary data area is used to store ECC (Error correction Code) and bad block information and file system related code. Its organizational relationship is shown in Figure 1:

The address of K9K8GOSUOM is sent into the chip by multiplexing 8 I/O ports. Such a design significantly reduces the number of chip pins and brings convenience for system upgrades. When CE and WP are low, setting WE low can write the command, address and data of K9K8G08UOM through the I/O port. Data is written into the chip on the rising edge of WE. Command Latch Enable (CLE) and Address Enable Latch (ALE) are used to distinguish whether the data of the I/O port is an order or an address. K9K8G08UOM has a 1G byte address space and requires 30-bit addresses, so the byte addresses need to be sent in five cycles: row low address, row high address, column low address, column middle address, and column high address. Both page read and program operations require the same five address cycles immediately following the corresponding command input. However, in a block erase operation, there are only three address cycles. Different operations are distinguished by writing different commands to the command register.

1.2 K9K8G08UOM controller technology

In this system, FPGA is used as the controller of K9K8G08UOM memory, which can independently complete various operations of K9K8G08UOM with very few software operations, thereby reducing the system’s additional expenditure on FLASH memory and improving the read and write speed. The control logic timing of FPGA is developed through the hardware language VHDL. VHDL language can complete the timing control of the basic operation of FLASH with its advantages of fastness, independence and readability. The following is a part of the read operation program developed in the form of a state machine in VHDL language.

The basic operation of K9K8G08UOM storage consists of three types: read operation, page programming operation, and erase operation. The flow chart is shown in Figure 2.

When performing a read operation, first set the chip select signal/CS of K9K8G08UJOM low through the FPGA port, then set the CLE command pin high, and send the read1 (0x00) command, and send it on the rising edge of WE. After the command is sent, set CLE low. Before sending the address, set ALE high, write 5 address cycles sequentially on each rising edge of WE, and then set ALE low to complete the address selection. Then send read2(0x30h) to start reading the data of the address unit.

Data page program operation is similar to read operation flow. Operations are performed in units of pages. When the R/Bur signal is low, it indicates that the FALSH is being written into, and when it is high, it indicates that the page programming operation is over.

The erase operation is carried out in units of blocks, that is, to erase 64 pages in a block at a time, and only 3 address cycles are needed when sending addresses.

Figure 3 is the data read by the host computer software after the data is stored in the K9K8G08UOM memory. It has been verified that the read data is consistent with the data written to the K9K8G08UOM memory.

2 The hardware part of NAND FLASkI Memory

In this design, the data input and output ports and control ports of FLASH are connected to the ports of FPGA through the conditioning circuit. Figure 4 shows its hardware connection circuit.
It can be seen from Figure 4 that FLASH data input and output ports I/00~7, control port/CE are connected to FPGA through chip SN54LV245; FLASH control ports cLE, ALE, /WE, /RE are connected through chip SN54LV245 and chip 74HCl4 Connected to ITGA. Among them, F-CLE, F-ALE, F-WE, F-RE, F-CE, and FR/Bur are the I/O ports of FPGA and the input and output ports of FPGA logic. The CLE and ALE signals are FLASH memory commands and address latch enable signals, /WE is a signal to ensure that commands, addresses, and data can be written into FLASH in a timely and correct manner, and the /RE signal controls the reading of data. The accuracy of these signals The degree is related to the realization of FLASH storage and reading functions. Therefore, the quality of these signals is directly related to the normal work of FLASH. After actual circuit debugging, these signals are interfered by other factors during the transmission process, and the signals are obviously distorted. After adding 74HCl4 (NOR gate) to the circuit, the signals will become smooth and accurate.

The chip SN54LV245 is an octal three-state bus transceiver. When DIR=1, the bus transmission direction is from A→B; when DIR=0, the bus transmission direction is from B→A. / OE is a chip selection signal. / 0E, DIR signal is controlled by FPGA internal programming logic.

In the FL and ASH interfaces, in order to ensure that the initial state of the /wE, /RE, /CE, and R/B control signals is invalid, the port value is pulled high by the hardware circuit. The write protection function is not used in this design, so the /WP port is also connected with a pull-up resistor.

3 Conclusion

Solid-state memory based on flash memory technology has high storage density, low power consumption, high reliability, small size and light weight, and the cost is also continuously reduced. It has a good application prospect in aviation applications. When designing the storage test” title=”storage test”>storage test system, the choice of large-capacity NAIXD FLASH memory greatly improves the storage and reading speed, and the design circuit structure is simple and easy to modify.

The Links:   CM20MD-12H DMF50260NFU-FW

Principles, requirements and future trends of digital video intercom

/a>Security” title=”Security”>Security” title=”Security”>Security” title=”Security”>Security list.

Digital Video Intercom” title=”Digital Video Intercom”>Technical Principles of Digital Video Intercom

The composition of the digital video intercom system generally includes several modules: indoor unit, ladder unit, switch, management unit, etc.

When a visitor comes to visit, dial the designated indoor unit through the ladder port machine. The ladder port machine digitizes the video and audio information of the visitor, encodes and compresses it and transmits it to the designated indoor unit. After the visitor is identified, press the unlock button to open the door lock of the stairway. At the same time, VoIP is implemented between the ladder machine and the indoor unit, and the two terminals can realize two-way voice intercom, which provides further communication and confirmation for the owner to identify the identity of the visitor.

Between the two indoor units or between the indoor unit and the management unit, the system provides two-way video and voice transmission functions. In terms of function realization, both the ladder machine and the management machine can be attributed to the indoor unit. The indoor unit has the most comprehensive functions, realizing audio and video compression transmission, receiving decompression Display and echo cancellation functions, and can be used as a realization terminal of various network value-added services.

Traditional building video intercom products are gradually developing in the direction of digitalization, networking, and intelligence. In addition to performing video intercom, remote unlocking, and alarm functions, video intercom products also It has realized value-added services such as remote video monitoring, abnormal alarm, access control, three-meter CC, information release, smart home control, Internet access, video on demand, and even mobile phone linkage. Most of these products have built-in powerful SoC processors and touch TFT displays Screen, especially the standard network function, brings more room for imagination to the product, and will more and more integrate digital media functions such as PVR, DPF digital photo frame, videophone, media player, etc., digital video intercom Quietly acted as another center of the digital family.

Digital video intercom product demand

(1) Security

Video intercom products are security products, and their basic function is still to meet the security needs of families and communities. Therefore, users hope that the video intercom system can provide further security functions while providing video calls and remote unlocking. If the owner is away, the activities of the elderly and children at home can be monitored remotely, and the management office or the resident can be notified immediately (such as by text message) when a fire, gas leak or thief enters the resident’s home.

(2) Stability

Video intercom products are security systems that require 24-hour operation, so users require the product to have excellent stability, and only stability can ensure safety.

(3) Practicality

Only practical products have strong vitality. The existing products in the market are not very practical. Some home-installed video doorbells may only be used once a week or two. The reason is that the functions are too simple to be practical. If residents are allowed to choose whether to buy or not, I believe many consumers will choose “no”. To make video intercom products popular with families, its practicality is the key. If you can browse your photo collection through the video doorbell, check the frequently used phone numbers, and collect monthly expenses and expenditure information, etc., the utilization rate of the equipment and the degree of attention will be greatly improved. Only by improving the utilization rate of the equipment can the product market be Really prosperous.

The Links:   G121XN01 V0 FF900R12IE4

Prediction and control of in-vehicle noise of monorail based on VA One

Taking the straddle monorail as the research object, the SEA noise prediction model of the monorail was established by using the statistical energy method software VA One, and the equivalent sound insulation treatment was adopted for the hollow aluminum profiles, and the ideal noise source was used as the load for the noise source. The main noise source was found out by predicting and analyzing the noise inside the vehicle. At the same time, the acoustic package was loaded on the whole vehicle, and the noise reduction effect was predicted and analyzed, which provided guidance for the subsequent noise reduction design and the development of low-noise monorail vehicles. and suggestions.

introduction

With the continuous development and progress of the economy, rail trains have become the main means of transportation in many cities due to their advantages of convenience, punctuality, speed, low pollution and low energy consumption, and constitute an important part of urban transportation development. Straddle-type monorail is favored by people because of its strong climbing ability, small turning radius, small footprint, low cost, fast and convenient, and environmental protection. With the large-scale application of urban rail trains, its noise problem has attracted more and more attention, and it is also a key indicator that affects its market competitiveness.

1. Establishment of calculation model and simulation calculation analysis

1.1 Establishment of SEA model

The vehicle model is reasonably pre-processed by relevant pre-processing software, and then imported into the statistical energy method software VA One. According to the basic assumptions and modeling principles of the statistical energy analysis model, the symmetry of the vehicle and the simulation of Statistical energy analysis (SEA) model was established.

In the process of establishing the vehicle SEA model, it is necessary to carry out reasonable subsystem division first.When building the vehicle model in VA One software, the modal similarity group method is used to simplify the vehicle model[4]. The vehicle body structure is simulated by the flat panel and single-curved panel subsystems, and the body aluminum profiles are treated with equivalent sound insulation, including the roof, side walls and floor. The sound field environment inside and outside the car is simulated by the three-dimensional acoustic cavity subsystem, and the external acoustic cavity subsystem is connected with semi-infinite fluid to simulate the external sound field environment without reflection.

1.2 Sound insulation performance parameters of vehicle SEA model and loading of noise excitation

During the operation of monorail trains, the main noise sources are powertrain parts (including motors and brake discs, etc.), air-conditioning units, etc. According to the actual load of the monorail train, in the process of establishing the vehicle interior noise prediction model, the main loads are: the noise excitation of the powertrain area and the noise excitation of the air-conditioning unit above the roof. The loading method is to use the ideal noise source to load the sound cavity at the corresponding position of the bottom of the car body and the top of the car body.

1.3 Calculation Results and Analysis of Main Contributing Noise Sources

The above model is for the case where no acoustic package is added to the whole vehicle. After adding the excitation load, the sound pressure level of the driver’s cab and passenger compartment is calculated. Since the load is an ideal noise source, the calculation results are only related to the test results in the lateral direction. Compare and guide. The sound pressure level in the driver’s cab is higher than that in the passenger compartment.

In order to find out the contribution of the subsystems that directly provide energy input to the noise inside the vehicle and the contribution of related subsystems to the noise at the target observation, before adding the acoustic material, the sound power contribution of the acoustic cavity subsystem at the target observation is calculated and analyzed to find out The main noise transmission path, so as to carry out noise reduction processing on the target observation.

Figure 1 shows the main energy input histogram of the acoustic cavity subsystem in the passenger compartment of the head car. It can be seen from the figure that the main energy of the acoustic cavity subsystem comes from the adjacent bottom acoustic cavity subsystem and the front acoustic cavity subsystem, and then respectively. Perform energy input analysis on these two acoustic cavity subsystems.

Figure 2 shows the main energy input histogram of its adjacent bottom acoustic cavity subsystem. It can be seen from the figure that the main energy of the acoustic cavity subsystem comes from the acoustic cavity subsystem at the powertrain.

From the above analysis, it can be seen that the main noise sources and main noise transmission paths at the target observation positions of the driver’s cab and passenger cab are: the noise of the powertrain part causes vibration of adjacent structural parts through the air, and is transmitted to the ears of the driver and passengers.

2 Vehicle interior noise control

Through the above analysis, we know that the main noise in the car comes from the powertrain part, and understand the main transmission path of the noise. Therefore, for the powertrain part, we load the corresponding sealed sound insulation cover: for the noise propagation path, the car body structure is loaded with acoustic packages such as sound absorption and insulation materials and damping materials for noise reduction. The model after loading the acoustic package is analyzed and calculated again, and the results are shown in Figure 3 and Figure 4.

It can be seen from the calculation results in the figure that after loading the corresponding acoustic package on the sound source and the noise transmission path, the noise level in the vehicle is well controlled.

3 Conclusion

In this paper, using the statistical energy method, based on the VA0ne software, a SEA model for predicting the interior noise of the monorail train is established, and the interior noise is simulated and analyzed, and the sound pressure level at the target observation position and the power input contribution of the interior noise are obtained. The noise transmission path in the vehicle is obtained, and then a reasonable acoustic package is loaded on the noise source and transmission path to control the noise. The research method in this paper can provide certain guidance for the selection of materials for the initial acoustic package design of monorail trains, the determination of the location of the acoustic package and the noise reduction treatment of specific locations in the vehicle.

The Links:   NL8060BC31-41D G121I1-L01 BSM150GT120DN2

10 basic knowledge commonly used by MCU, collected!

From the appearance, if the pins of both buzzers are placed upward, it can be seen that the one with the green circuit board is the source buzzer, and the one without the circuit board and sealed with black glue is the active buzzer. buzzer.

1. If the MCU has a serial port peripheral, add a level conversion chip, such as MAX232 and SP3485, which are RS232 and RS485 interfaces.

2. RS485 adopts differential signal negative logic, +2~+6V means 0, -6~-2 means 1. There are two-wire and four-wire connections. The four-wire system is a full-duplex communication method, and the two-wire system is a half-duplex communication method. In RS485, the master-slave communication method is generally used, that is, a master with multiple slaves.
  
3. Modbus is a protocol standard that can support a variety of electrical interfaces, such as RS232, RS485, and can also be transmitted on various media, such as twisted pair, optical fiber, wireless.
  
4. Many MCU serial ports have their own FIFOs. The transceiver FIFO is mainly to solve the problem of low CPU efficiency due to frequent serial transceiver interrupts.

If there is no FIFO, the data will be interrupted and processed once without sending and receiving data. With FIFO, an interrupt can be generated to process the data after sending and receiving several data continuously (depending on the depth of the FIFO), which greatly improves the efficiency.

5. When some engineers are debugging their own systems, as soon as the system runs away, they immediately introduce a watchdog to solve the problem. Why do programs run away without thinking?

The program running away may be a bug of the program itself, or it may be a problem of the hardware circuit (it is susceptible to interference or itself is the source of interference). It is generally recommended that when debugging your own system, do not add a watchdog first, and then make up after the debugging is fully stabilized (except for the crisis of product safety and personal safety).

6. How to distinguish active buzzer and passive buzzer?

From the appearance, if the pins of both buzzers are placed upward, it can be seen that the one with the green circuit board is the source buzzer, and the one without the circuit board and sealed with black glue is the active buzzer. buzzer.

The active buzzer can sound continuously when it is directly connected to the rated power supply, while the passive buzzer, like the electromagnetic speaker, needs to be connected to the audio output circuit to sound.
  
7. The purpose of the voltage comparator is mainly the generation and transformation of the waveform, the interface from the analog circuit to the digital circuit.
  
8. Common ways of low-power wake-up: After the processor enters low-power, many activities are stopped. When an interrupt occurs, the processor can be woken up and returned from low-power mode to normal operation mode.

Therefore, before entering the low power consumption mode, it is necessary to configure the interrupts of various on-chip peripherals and allow them to continue to work in the low power consumption mode. If not, only a reset and power cycle can end the low power mode. After the processor wakes up, the interrupt service routine is executed first, and then the code in the main program is executed after exiting.

9. Register the interrupt service function: The interrupt service function has been written, but when the interrupt event occurs, the CPU still cannot find it, because we are still missing the last step: register the interrupt service function.

There are two methods for registration: one is to directly use the interrupt registration function. The advantage is that the operation is simple and the portability is good. The disadvantage is that the execution efficiency is reduced due to the remapping of the interrupt vector table into SRAM. , the advantage is very efficient, and the portability is determined not to be high.
  
10. Many MCUs provide digital power VDD/GND and analog power VDDA/GNDA. It is usually recommended to use two different 3.3V power supplies for power supply. However, in order to save cost, a single 3.3V power supply can also be used, but VDDA/GNDA should be separated from VDD/GND through an Inductor.

Generally, GNDA and GND should be connected together eventually. It is recommended to use a wire-wound inductor to connect and connect the contacts as close as possible to the chip (the inductor is best placed on the back of the PCB).

The Links:   BSM10GD120DN2 CM75DY-34A BUY-igbt