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TDK Hungary winds up HUF 1 bln R&D project

 MTI – Econews
 Tuesday, July 30, 2019, 12:15

Japanese-owned TDK Hungary Components Kft. said on Tuesday it has wound up a HUF 1.03 billion research, development and innovation project, state news wire MTI reported. TDK won HUF 258 million in EU and state grant money for the project.

The company announced the launch of the project to develop the next generation of aluminum electrolytic capacitors in December 2018, MTI recalled.
TDK Hungary said it employs 2,500 people at its base in Szombathely in western Hungary. It posted revenue of EUR 254 mln in its business year that ended on March 31, 2018.

TDK Hungary winds up HUF 1 bln R&D project

 MTI – Econews
 Tuesday, July 30, 2019, 12:15

Japanese-owned TDK Hungary Components Kft. said on Tuesday it has wound up a HUF 1.03 billion research, development and innovation project, state news wire MTI reported. TDK won HUF 258 million in EU and state grant money for the project.

The company announced the launch of the project to develop the next generation of aluminum electrolytic capacitors in December 2018, MTI recalled.
TDK Hungary said it employs 2,500 people at its base in Szombathely in western Hungary. It posted revenue of EUR 254 mln in its business year that ended on March 31, 2018.

TDK Hungary winds up HUF 1 bln R&D project

 MTI – Econews
 Tuesday, July 30, 2019, 12:15

Japanese-owned TDK Hungary Components Kft. said on Tuesday it has wound up a HUF 1.03 billion research, development and innovation project, state news wire MTI reported. TDK won HUF 258 million in EU and state grant money for the project.

The company announced the launch of the project to develop the next generation of aluminum electrolytic capacitors in December 2018, MTI recalled.
TDK Hungary said it employs 2,500 people at its base in Szombathely in western Hungary. It posted revenue of EUR 254 mln in its business year that ended on March 31, 2018.

Low-ESR tantalum capacitors make a difference in circuit designs

Low-ESR tantalum capacitors can improve circuit power efficiency, reduce heat generation for the circuit, and increase low-term reliability

By Charles Pothier, vice president of marketing, Tantalum Capacitor Division, Vishay Intertechnology

When choosing a capacitor for any application, there are a few key characteristics that must be understood in order to analyze its suitability for the circuit. In a simple capacitor equivalent circuit model, there are three key characteristics that affect circuit performance: capacitance, equivalent series resistance (ESR), and inductance. The magnitude of these elements — and how they change over temperature, frequency, and applied voltage — are different for each capacitor technology.
In this technical note, we will examine the ways in which ESR in tantalum capacitors affects circuit performance. ESR is the sum of all of the purely resistive contributors to the capacitor’s impedance. As such, it is the characteristic that creates losses due to heating. It also affects the magnitude of charge and discharge currents as the capacitor does its work
In a solid tantalum capacitor, the components that contribute to ESR are the resistivity of the:
Solid electrolyte system (MnO2)
Dielectric layer (Ta2O5)
Terminations, lead frames, and other elements that provide connection to the PCB
Solid tantalum capacitor manufacturers can make improvements in physical design and materials that reduce the overall ESR of the capacitor. These lower-ESR capacitors will lead to reductions in heat generation within the capacitor, thus improving overall circuit efficiency and long-term reliability. Reductions in ESR will also improve the capacitor’s ability to supply higher currents during charge and discharge cycles to improve circuit performance. Typical impedance (Z) and ESR data for a range of popular values are shown in Fig. 1.
Fig. 1: Typical impedance (Z) and ESR data for a range of popular values.
Two primary functions that tantalum capacitors are ideally suited for are bulk energy storage and waveform filtering.
Bulk capacitanceIn addition to maximum working voltage and voltage derating, an important characteristic of any capacitor is its ability to store an electrical charge. Some applications require the capacitor to store large amounts of charge.
Solid tantalum devices are well-suited for bulk energy storage due to their high and stable capacitance values and are widely used to hold up voltage rails during times of peak current demand. Here, two factors must be considered. The first is the total capacitance required to supply the required energy for the necessary time. In some cases, a single tantalum capacitor is sufficient, but in more demanding applications, multiple capacitors may be configured in parallel so that their capacitance values are cumulative and the combined resistance of the array is reduced. The second factor is the ESR of the capacitors. Lower ESR results in higher deliverable current levels and lower voltage drop during discharge for improved circuit performance.
An example is the bulk capacitance required on a 3.3-V rail that supplies power to a microprocessor. During turn-on, and in the application when processing demands are high, the microprocessor will have high current demands that must be satisfied. The ability of the capacitors to effectively deliver this bulk energy is often characterized with a specification called the “slew rate,” which is defined as “idle current” to “peak current” with a specified slope “A/µs.” During times of peak demand, it may be necessary to keep the rail voltage within a required specification range (for example, a drop of less than 10% = 0.33 V). Capacitors with lower ESR can provide higher discharge currents with reduced heat generation to meet these demands more quickly and efficiently.
Designers may actually place several lower-capacitance multilayer ceramic capacitors (MLCCs) close to the processor for short-term current supply and then add larger bulk storage capacitors (tantalum, polymer, or aluminum electrolytic devices) slightly farther away to meet longer-term current demands. The ultra-low ESR of the MLCCs allows for very high instantaneous currents, but their limited capacitance means that they are able to supply the required current for only a short period of time. After that time, the bulk capacitors can take over and meet required circuit demands. When lower-ESR tantalum capacitors are used in this application, there is less reliance on the MLCCs and fewer of them are required. This saves PCB board space as well as component costs. They also improve board-level reliability with their more rugged construction.
Low ESR capacitors are available in a number of case sizes.
Another advantage of using low-ESR tantalum devices as bulk energy capacitors is reduced heat generation during charge/discharge cycles. This improves circuit power efficiency and results in a lower operational temperature for the circuit. It may also allow for the use of smaller power supplies for further cost savings.
Waveform filteringWhen low-ESR capacitors are used for smoothing a signal, they reduce the amount of ripple current that appears on the DC bus, such as output filter capacitors in switch-mode power supplies (SMPS). This is accomplished by allowing for higher charge/discharge currents to better follow the voltage cycles and supply energy during any peaks and valleys in the waveform. As the ripple current (peak to peak) is reduced, less heat is dissipated on each charge/discharge cycle. Lower-ESR (and lower-inductance) capacitors also allow ripple filter capacitors to be used effectively in circuits with higher-frequency AC noise components.
Consider the Vishay TR3 low-ESR product line. The TR3’s best-in-class ESR yields improved circuit electrical performance, power efficiency, and reliability (lower operating temperatures). Based on case size, a number of capacitance/voltage (CV) options are available and each combination has a specific ESR value (see Fig. 2 for the D case example).
Fig. 2: Capacitance/voltage options with ESR values for Vishay’s TR3 low-ESR tantalum capacitors.
In addition to ESR, designers must take voltage rating, ESL, DCL, and dielectric properties into consideration for filter capacitor designs. Tantalum capacitors in general allow for very low-profile and compact designs and enable high PCB-level reliability due to their solid construction.
About the authorCharles Pothier currently serves as the vice president of marketing for Vishay’s Tantalum Capacitor Division. He has previously held the positions of marketing manager at Teradyne and electrical engineer for Lockheed Martin. Mr. Pothier holds a B.S. in electrical engineering from Northeastern University and an M.S. in administration from Boston University.

Is 5G ready for prime time?

There are nearly two dozen 5G smartphone designs expected to be available this year and researchers are forecasting over 1 billion subscribers by 2024, with minimal rollouts this year

Image: Shutterstock.By Gina Roos, editor-in-chief

We asked ourselves if 5G is ready for widespread adoption, and the answer is no. However, there are nearly two dozen 5G smartphone designs expected to be available this year and researchers are forecasting over 1 billion subscribers by 2024, with minimal rollouts this year.
Though we still have a long way to go before 5G deployments usurp the previous-generation 4G/4G LTE cellular networks, component manufacturers — from RFICs and modems to connectors and oscillators — are making it happen with continued new product development that delivers precision performance in small packages and higher integration while keeping an eye on costs. In addition, they are helping drive 5G commercialization by partnering with mobile operators and OEMs to test and fine-tune devices and networks.
Over the past couple of years, chipmakers in particular have been on the fast track in developing modems and RF front ends for the next generation of cellular networks. Today, many of them have rolled out chipsets and platforms that include radio frequency ICs (RFICs), system-on-chips (SoCs), application-specific integrated circuits (ASICs), cellular ICs, and millimeter-wave (mmWave) ICs.
With the promise of ultra-low latency, higher data rates, and greater capacity, higher-performing RF power devices are needed to deliver higher integration and lower power consumption. A number of architectural complexities have been introduced by 5G due to MIMO antenna configurations.
In addition, 5G radio equipment needs to operate in traditional cellular bands and other microwave and mmWave bands, but to ensure a reliable flow of data across the frequency bands, it will be essential to improve output power and energy efficiency of the network infrastructure. The answer may lie in gallium nitride (GaN) technology for power semiconductors.
But RF chipmakers aren’t the only component manufacturers making strides in the 5G space. Frequency control devices for timing and clocking are critical components in high-data-rate transmissions for 4G and 5G networks. Oscillator manufacturers are developing new devices that tackle two big consumer demands: fewer service disruptions and better user experiences.
In addition, MEMS OCXOs are delivering benefits for these higher-speed networks, including high reliability, tight stability, and the ability to withstand harsh environments. They can be used as an alternative to quartz OCXOs, solving challenges such as sensitivity to environmental conditions, which require protective measures to solve the problem. But there are more advantages, including size, weight, and power consumption, that make these devices worth a second glance for communications equipment.
In the interconnect, passive, and electromechanical (IP&E) space, connectors and cable assemblies also have a key role to play in high-speed data transmission. 5G networks will have a big impact on connector reliability and signal integrity, and for 5G antenna systems, these interconnects need to step up their thermal, speed, and EMI performance while providing a low-cost solution. Currently, there are 5G-ready connectors in the market, though more optimization work is under development.
And once you’ve got all the pieces of the 5G puzzle, you’ve got to master 5G testing. As cellular speeds increase, so does test complexity, which includes expanded test requirements. These include new tests for standards compliance, EMI/EMC requirements, and over-the-air (OTA) behavior understanding, along with more test cases to cover new functionality.

SiC devices deliver higher power efficiency in aircraft

SiC-based MOSFETS and Schottky barrier diodes reduce power losses and enable higher power density, while reducing the complexity of cooling systems and the overall architecture of an aircraft’s power supply system
By Maurizio Di Paolo Emilio, contributing writer
Silicon carbide (SiC) is a next-generation material that plans to significantly reduce power losses and enable higher power density, voltages, temperatures, and frequencies while reducing heat dissipation. High-temperature operability reduces the complexity of cooling systems and therefore, the overall architecture of the power supply system.
The aviation industry has experienced rapid growth recently compared to the last few decades, and by 2020, it is estimated that air traffic will grow by 5% per year. The new aerospace world has found new power management solutions in SiC devices for power supply and motor control.
SiC promises low-weight components to reduce fuel consumption and emissions in the aeronautics industry, and the stable operability of the SiC MOSFET at higher operating temperatures, for example, has attracted researchers’ interest for high-power-density power converters.
SiC devices for aircraftMore Electric Aircraft (MEA) has been a research and development topic focused on the aeronautics industry for more than 10 years, and it has represented a revolution in the design and production of electronic systems. The result has led to the expansion of new power solutions from a predominantly auxiliary support network toward a significantly higher energy requirement to power not only flight entertainment systems (rear flat screens) but also environmental control devices, electric motors, and a myriad of safety systems and sensors throughout the aircraft.
The development of new semiconductor devices capable of tolerating high voltages and currents using materials such as SiC and gallium nitride (GaN) has provided a decisive and positive change for power electronics. SiC has a wide bandgap, high thermal conductivity, and high resistance to electric field breakage, which helps reduce power losses. A particular area of application is electric vehicles, in addition to the aerospace sector, wherein the demand for greater compactness, high power density, and high-temperature operation are of critical importance.
Silicon has been the primary technology in many applications, but with the emergence of these new broadband power semiconductors — in particular, SiC MOSFETs and SiC diodes — designers of power electronics can leverage new higher switching speeds and reduce losses compared to traditional silicon-based technology.
Furthermore, SiC MOSFET technology promises to significantly reduce the size and weight of avionic power switches, with significant reductions in fuel consumption and emissions, in line with the objectives of various national governments. The aviation industry has recognized the potential benefits of SiC with an evident impact on all areas of the power supply system.
In an aircraft, we can identify various electronic systems that use power components. The AC/DC and DC/DC power converters are used for various solutions both for high voltage and low voltage (28 V).
One of the critical design problems for power electronics and motor drive circuits using SiC devices is the management of the gate drive conditioning circuit. Managing gate timing is a serious challenge. One approach is to balance the speed of the SiC device to ensure that losses are kept to a minimum, and this can be done with an accurate gate driver design.
In the last few years, 1,200-V SiC MOSFETs available on the market from multiple suppliers have reached an outstanding quality level in terms of high channel mobility, oxide lifetime, and threshold voltage stability.
Solutions for aircraftThe new generation 1,200-V SiC MOSFETs and 1,200-V SiC Schottky barrier diodes (SBDs) from Microchip Technology Inc., via its Microsemi subsidiary, as an example, are suitable for use in power supply and control applications of the switching mode in commercial aviation but also in the automotive sector. One example is the 40-mΩ MSC040SMA120B MOSFET that offers high short-circuit resistance for reliable operation.
SiC MOSFETs and SiC SBDs are designed with a high repetitive capacity of unclamped inductive switching (UIS) at rated current, without degradation or failure. The integration of SiC devices in the on-board recharge and the DC-to-DC power supply conversion systems allows a higher switching frequency and lower losses (Fig. 1).
An important parameter in evaluating SiC MOSFETs is the avalanche ruggedness, which is assessed through the UIS test. Avalanche energy shows the ability of the MOSFET to survive transients sometimes incurred when driving inductive loads.
Fig. 1: Dynamic characteristics of Microsemi’s MSC040SMA120B MOSFET. (Image: Microsemi)
SiC MOSFETs offer 10× less failure-in-time (FIT) speed than IGBTs. They offer similar nominal voltages, while SBDs complete the robustness of the SiC MOSFET with UIS values 20% higher than other typical solutions. They also offer better efficiency at higher switching frequencies than IGBTs, a reduced system size and weight, high temperature operating stability (175°C), and significant savings on cooling costs.
Because silicon carbide has a higher critical rupture field than silicon, SiC MOSFETs can achieve the same rated voltage in a smaller package than silicon MOSFETs. The SFC35N120 from Solid State Devices Inc. (SSDI) is one example. The 1,200-V SiC power MOSFETs offer a typical fast switching speed of less than 30 ns. With a resistance of 190 mΩ max at 150°C, this device facilitates parallel configurations and reduces the need for thermal management hardware such as fans and heat sinks (Fig. 2).
Fig. 2: Package styles available for the SSDI’s SFC35N120. (Image: Solid State Devices)
The collaboration between Analog Devices Inc. and Microsemi brought to market the first high-power evaluation board for SiC half-bridge power modules with a switching frequency up to 1,200 V and 50 A @ 200 kHz. The card was designed to improve the reliability of the design while reducing the need to create additional prototypes to save time, as well as to reduce costs and time to market. The high-power evaluation board is suitable for applications such as electric vehicle (EV) charging, onboard EV/HEV charging, DC/DC converters, switched-mode power supplies, high-power motor control and actuation systems aviation, magnetic resonance, and X-rays.
The 1,200-V CAS325M12HM2 SiC power supply module, configured in a SiC half-bridge topology, from Wolfspeed, a Cree company, represents a new generation of all SiC power modules housed in a high-performance 62-mm package. This module uses 1,200-V C2M SiC MOSFETs and 1,200-V Schottky diodes. The superior thermal characteristics of SiC devices, together with the design and packaging materials, allow this module to operate at 175°C, which is a crucial advantage for many industrial, aerospace, and automotive applications (Fig. 3).
Fig. 3: The Wolfspeed CAS325M12HM2 module. (Image: Wolfspeed/Cree)
ConclusionThe SiC MOSFET and SiC SBD product lines increase the efficiency of power systems compared to silicon MOSFET and IGBT solutions while reducing the total cost of ownership, allowing scaled systems as well as smaller and cheaper cooling.
One of the main advantages of SiC-based switching devices is operation in hostile environments (600°C) in which conventional silicon-based electronics cannot work. The ability of silicon carbide to operate at high-temperature, high-power, and high-radiation conditions will improve the performance of a wide variety of systems and applications, including aircraft, vehicles, communications equipment, and spacecraft.
Today, SiC MOSFETs are long-term reliable power devices. In the future, expect to see multi-chip power or hybrid modules play a more important role in the SiC world.
This article was originally published on EE Times. 

Technology breakthrough yields ultra-thin transistors

Researchers at the Vienna University of Technology developed ultra-thin transistors, with novel insulators, from 2D materials
By Gina Roos, editor-in-chief
Researchers at the Vienna University of Technology claim the next big step in miniaturization of transistors, which has been a challenge in keeping up with Moore’s Law. Researchers have developed ultra-thin transistors, with novel insulators, from 2D materials, consisting of an atom-thick layer of material. Exhibiting excellent electrical properties, the new transistor technology can be reduced to a very thin thickness.
Ultra-thin semiconductors can be fabricated from 2D materials with a few atomic layers, said Professor Tibor Grasser, the Institute of Microelectronics at Vienna University of Technology, in a press release. “But if you want to build an extremely small transistor, that’s not enough. In addition to the ultra-thin semiconductor, you also need an ultra-thin insulator.”
A schematic sketch of the ultra-thin transistors (red-blue: the insulator). (Image: TU Wien)
Grasser said that this is due to the fundamental structure of a transistor in which current flows from one side of the transistor to the other if a suitable electric field is generated in the middle by the application of an electrical voltage. Between the electrode and the semiconductor itself is the insulating layer.
To miniaturize this layer and the transistor, the researchers, including Yury Illarionov, a postdoc on Tibor Grasser’s team, used an ultra-thin material — in this case, ionic crystals — for both the semiconductor and insulator, indicating improvements in the electronic properties.
The team decided to use an insulator made of an atomically thin layer of calcium fluoride, produced at the Joffe Institute in St. Petersburg, where Illarionov was a researcher before transferring to TU Vienna. The transistors were manufactured at the Institute of Photonics at the Vienna University of Technology.
Grasser said that the first prototype exceeded their expectations. “In recent years, we have repeatedly received different transistors to investigate their technical properties, but we have never seen something like our transistor with calcium fluoride insulator.”
The team is now working on a combination of insulators and semiconductors to see which will work best, as well as improvements in the production processes for the material layers. They believe that it will likely be several years before the technology can be used for commercial computer chips. The development of these smaller and faster transistors could be the next big step in the computer industry, returning to Moore’s Law of doubling the number of transistors on a chip every two years.
The new technology was first presented in Nature Electronics.

Sensor-actuator device could add touch to virtual and augmented reality

Researchers at UC Berkeley College of Engineering have found a way to potentially add touch to VR/AR applications in clothes and other wearables
By Gina Roos, editor-in-chief
Researchers at UC Berkeley College of Engineering recently announced that they developed a piezoelectret-based device that is a sensor and actuator. The device vibrates as feedback, similar to how it works in smartphones. But this technology is also very flexible, lending itself to be integrated into clothing and other wearable technologies.
Researchers believe that this technology could significantly improve the user experience in augmented and virtual reality (AR/VR) applications, changing the way they see and hear. In fact, they believe that it could provide touch feeling in immersive virtual experiences in the future.
In addition, the vibrations generated by the actuator can be customized, which could be used to help people with visual or hearing impairments communicate via vibrations.
The sensor-actuator patch is about 150 µm thick, similar to the diameter of a human hair. (Image: Adam Lau, UC Berkeley College of Engineering)
“There are many applications for this technology that can sense motion and give haptic feedback,” said Liwei Lin, mechanical engineering professor and co-director of the Berkeley Sensor & Actuator Center (BSAC), in a press release. He is also one of the lead authors of the technical paper published in ACS Nano. “One application is AR/VR. Right now, if you are playing a game and hitting a wall, you only hear a sound. With our device, the sensor can detect if you are going to hit something, and the actuator can vibrate to simulate a physical impact.”
The ability to achieve both sensor and actuator functions is based on an innovative sandwich structure that harnesses piezoelectricity, said Juwen Zhong. (Image: Adam Lau, UC Berkeley College of Engineering)
Juwen Zhong, a postdoctoral researcher at BSAC and a lead author on the paper said, the that device is 150 µm thick, which is similar to the diameter of a human hair. “Its flexibility and its ability to achieve both sensor and actuator functions is based on an innovative sandwich structure that harnesses piezoelectricity.”
The outside layers of the sandwich structure consist of fluorinated ethylene propylene elect films, while the Ecoflex spacer middle layer is coated with gold aluminum electrodes on top and aluminum electrodes on the bottom.
The sensor function can generate electrical outputs without a power supply, which can turn on the actuator via electrostatic force to generate the vibrations that can be felt by human skin. Today, the actuating mode can generate up to 20 meganewtons (MN), similar to a cellphone. It can also sense objects as light as a dandelion seed.
Zhong said that this device outperforms popular piezoelectric materials, showing a high piezoelectric coefficient and low driving voltage. This is key to improving the sensor’s sensitivity and the amount of electricity needed to power the actuator, he said.
The prototype has only nine pixels, but researchers would like to add more “piezoelectric pixels” that would enable vibrations that mimic different textures. They also plan to work on lowering the voltage required to power the device.