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High-speed data transmission interfaces such as USB, HDMI, and Ethernet use differential signaling due to its superior noise immunity. Even so, some noise still appears. To remove it, we need to understand where it comes from and why.

Transphorm Inc of Goleta, near Santa Barbara, CA, USA — which designs and manufactures JEDEC- and AEC-Q101-qualified gallium nitride (GaN) field-effect transistors (FETs) for high-voltage power conversion — and fabless firm Weltrend Semiconductor Inc of Hsinchu Science Park, Taiwan (which specializes in the design, testing, application development and distribution of mixed-signal/digital ICs in power supplies, motor controls and image processing) have announced the availability of two new GaN system-in-packages (SiPs). When combined with Weltrend’s flagship GaN SiP launched in March 2023, the new devices establish the first SiP product family based on Transphorm’s SuperGaN platform...

Deposition equipment maker Aixtron SE of Herzogenrath, near Aachen, Germany says that its G10-SiC chemical vapor deposition (CVD) epitaxy production platform has been chosen by discrete semiconductor and passive electronic component maker Vishay Intertechnology Inc of Malvern, PA, USA for its in-house silicon carbide (SiC) epitaxy needs for power device manufacturing. The system will be delivered to Vishay’s automotive-certified Newport fab in South Wales. With its flexible dual-wafer-size configuration of 9x150mm and 6x200mm, the G10-SiC supports the transition between wafer diameters...

Silicon Labs has announced its first-ever family of SoCs targeted at energy harvesting applications.

About time keeping, the definition of “sidereal” is “of or with respect to the distant stars (i.e. the constellations or the fixed stars, not the sun or planets)”, as defined after a google search. With that in mind, a quick and admittedly simplistic look at keeping earthly time is shown in Figure 1.

 

Figure 1 A comparison between solar days of 24 hours and sidereal days of 23 hours, 56 minutes, and 4.091 seconds.

As the earth moves around the sun in its yearly orbit, the absolute direction in which some fixed point on the earth’s surface that is aimed directly at the sun changes. We who sit on the earth at some particular place, maybe in our backyards, see the sun reach its peak in the sky once every twenty-four hours and we call that a solar day. Disregarding leap years, leap seconds, and the like; our wristwatches, tabletop alarm clocks, and other timepieces keep track of our personal time on a solar day basis.

Measured with respect to absolute space, however, the solar day requires an earth rotation per “day” of slightly more than 360°. Thus, when we take the universe at large as some fixed entity, with respect to that entity, the earth completes an exact 360° rotation in an average time of only 23 Hours, 56 Minutes, 4.091 Seconds which is a shorter time span.

That shorter time span is a sidereal day which differs from and is slightly less than a solar day.

Have you checked your watch lately?

John Dunn is an electronics consultant, and a graduate of The Polytechnic Institute of Brooklyn (BSEE) and of New York University (MSEE).

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Available with four frequency options each covering from 8 kHz to 12.75 GHz, 20 GHz, 31.8 GHz or 40 GHz, the new R&S SMB100B microwave signal generator from Rohde & Schwarz brings excellent output power, spectral purity, very low close-in phase noise, and practically no wideband noise to analog microwave signal generation.

The new R&S SMB100B analog microwave signal generator from Rohde & Schwarz offers outstanding, market-leading performance for analog signal generation up to 40 GHz in the midrange class. Thanks to its easy operation and comprehensive functionality, the versatile R&S SMB100B is now the first choice for all applications requiring clean analog signals or high output power from 8 kHz to 40 GHz. Typical applications include testing radar receivers, semiconductor components, upconverters, downconverters or amplifiers. Thehigh output power and low phase noise make it ideal as a source for simulating interferers for blocking tests.

The R&S SMB100B microwave signal generator features a signal purity which combines very low single sideband (SSB) phase noise, excellent non-harmonics suppression, and low wideband noise for all carrier frequencies. For users seeking even better close-in phase noise and frequency stability, and less temperature-based variation in performance, in addition to the standard OXCO reference oscillator, a higher performance version is available for all frequency ranges. In addition to the conventional 10 MHz reference frequency, users can choose optionally 1 MHz to 100 MHz as well as 1 GHz reference frequency signals. Optional high output power of measured 25 dBm at 20 GHz and 19.5 dBm at 40 GHz is activated by keycode, so users can install it at any time. Considering the microwave frequency range covered by the instrument, the R&S SMB100B microwave signal generator is light (10.7 kg) and compact, fitting in a 19” rack and only two rack units in height.

The level accuracy of the output directly from an R&S SMB100B itself is excellent. With each increase in the frequency of the required signal, the challenge of obtaining the correct level input to a device increases: The R&S SMB100B supports two additional features to compensate for path losses and variations in the signal caused by setups with additional test fixtures, cables or amplifiers. These features help to provide the wanted power level at the reference plane i.e. at the input of the device under test. One of them, the user correction function (UCOR), compensates if the frequency response of the setup is known and stable. However, there are still unknown factors especially if the setup includes additional active devices such as an amplifier. Then 1/2 the frequency response of the setup with an external additional amplifier can vary over level or temperature. Closed-loop power control can compensate for all these variations by continuously measuring the input level to the DUT i.e. at the wanted reference plane with a suitable R&S NRP power sensor feeding its measured level back to the generator to adjust the output power accordingly. More details about this use case can be found in the application note 1GP141.

The R&S SMB100B is user-friendly in every detail. Users can create their own customized menus, so that the parameters they most use are always available. They can generate code to automate measurements first made manually with the SCPI macro recorder while the measurements are set up and run, then use the code generator to export the instructions in languages such as MATLAB. Thanks to R&S Legacy Pro, the R&S SMB100B (and other Rohde & Schwarz test equipment) can be used to emulate other instruments such as R&S SMB100A or competitor instruments directly, as a drop-in replacement using the existing code.

The new R&S SMB100B microwave signal generator up to 40 GHz is now available from Rohde & Schwarz and expands the R&S SMB100B analog signal generator family with its established RF models up to 6 GHz.

The post Rohde & Schwarz introduces new R&S SMB100B microwave signal generator for analog signal generation up to 40 GHz appeared first on ELE Times.

Having delivered 13% revenue growth in FY24, Tata Elxsi is among the world’s leading design and technology service providers across industries including Automotive, Broadcast, Communications, Healthcare, and Transportation. They mark high competence in servicing through design thinking and development in digital technologies like IoT, Cloud, Mobility, Virtual Reality, and AI.

Jayaraj Rajapandian, Head of Avionics, Transportation, Tata Elxsi

Rashi Bajpai, Sub-Editor at ELE Times spoke with Jayaraj Rajapandian, Head of Avionics, Transportation, Tata Elxsi on various aspects of aerospace/ aviation – from what’s trending to what the future holds for the industry.

This is an excerpt from the interaction.

 

 

ELE Times: What are some of the latest trends in Aerospace electrification?

Jayaraj Rajapandian: The aerospace industry is rapidly evolving, with many innovations redefining the field. One of the latest advancements is in aerospace electrification. This is a major boost to meet the UN sustainable development goals set for the Aerospace industry. It involves implementing electric propulsion technologies such as electric motors and turbo-electric propulsion by using electric energy to power the aircraft fully or in hybrid mode.

The electrification of propulsion systems made Urban Air Mobility (UAM) vehicles a reality and it is a step closer to commercial operation. Smaller aircraft and drones provide decreased emissions, quieter operation, and improved efficiency. Electrical actuators drive fuel efficiency and are replacing the hydraulic-driven actuators.

Hybrid-electric propulsion systems combine traditional fuel-powered engines with electric propulsion systems. The larger aircraft adapts them to increase fuel efficiency and reduce emissions.

Sustainable Aviation Fuels (SAFs) can be used to reduce aviation’s environmental impact. However, the investment to scale the SAF production is to be monitored against aviation demands.

Electric Vertical Takeoff and Landing (eVTOL) vehicles enable vertical takeoff and landing, which reduces the dependency on infrastructure like a dedicated runway. Vertiport unlocks the potential for urban air mobility. These vehicles will be incorporated more for logistics and aerial combat vehicles.

Moreover, advancements in battery technologies are seeing exponential growth in fuel cells for storage, effective power conversion, and distribution, necessitating effective battery management solutions. Lithium polymer batteries enable long-endurance owing to their lower weight and higher power storage.

ELE Times: Give us some insights into the future innovations in Unmanned Air Systems.

Jayaraj Rajapandian: Unmanned Air Systems (UAS) have been incredibly useful in improving efficiency, reducing costs, reaching remote and inaccessible areas, improving defence systems, and, most importantly, enhancing safety. The primary focus is to improve autonomous navigation and control by incorporating cutting-edge technologies such as Artificial Intelligence (AI) and Machine Learning (ML) to operate effectively in complex environments and all-weather conditions and push the endurance for extended missions.

Currently, commercial usage of UAVs is being monitored by regulators, mainly when operating beyond the visual line of sight (BVLOS). However, advanced sensor and payload technologies such as LiDAR and thermal imaging systems could help improve the availability and reliability.

Unmanned Combat Systems consist of aerial, land, and underwater drones. Unmanned aerial vehicles are used to gather intelligence, conduct surveillance, and reconnaissance (ISR), and carry munitions. Governments worldwide recognize Unmanned Combat Systems as an asset comparable to manned fighter jets as they consume a significant portion of defence budgets. Researchers are exploring swarm intelligence to enable several drones to work together and operate collectively, ensuring the mission is never compromised, even if many UAVs are lost.

ELE Times: Elaborate on some of the latest technologies in avionics development for advanced navigation and control.

Jayaraj Rajapandian: In the past couple of decades, satellite-based navigation and communications systems have become more widespread, electronic systems have become more scalable, and higher redundancy has become more common in recent aircrafts. Fly-by-wire flight control systems have replaced mechanical controls with electronic interfaces, allowing for precise and adaptive control of aircraft flight surfaces. Using a single pane of glass in the cockpit flight decks turned the operation to be more seamless. However, by the mid-2030s, ICAO predicts that airspace will witness double the current traffic and the industry requires more than incremental innovation, a transformation is needed.

Currently, the focus is on bringing compact form factors and platforming the systems. Aerospace OEMs and technology partners are collaborating on this next journey. RISC-V-based processing units are gaining attention for their security features and custom-built capabilities that meet OEMs’ needs. The collaboration on Avionics such as FMS, used in different aircraft supplied by various vendors, to create a unified family of products signifies a strategic move towards standardization and interoperability in the aviation industry. This reduces inventory costs for OEMs and the training costs of airlines.

Innovations to counter deceived sensors to manage spoofing, anti-jamming and to distinguish friends from foes, and security in communications are gaining attention. A growing number of regional players are developing Avionics for UAVs, breaking the technology entry barrier. To stay competitive and relevant, defense OEMs require transformational effort to reduce cycle time which typically takes 5 to 7 years. Digital Twin, Investment in Big-Data processing with High Processing Computing capability can accelerate this cycle time.

Tata Elxsi’s advanced process flow can be used in the development of a cloud-based Digital Twin of a sub-system. The features developed from the Digital Twin are scalable and can be used for multiple systems simultaneously.

ELE Times: How can AI/ML be adopted for aerospace design and maintenance?

Jayaraj Rajapandian: With AI and ML capabilities, aerospace design and maintenance can improve efficiency, reduce downtime, and improve the health of systems. AI and ML can analyze extensive datasets from simulations, past designs, and real-world operations to pinpoint the most effective configurations for aircraft components, structures, and systems.

AI and ML tools also help to build virtual prototyping and testing of aircraft systems and components. It generates precise simulations using high-processing computers, anticipating performance traits, and fine-tuning design parameters. More importantly, AI and ML algorithms also help in predictive maintenance. These algorithms can analyze sensor data from aircraft systems and components to detect anomalies, predict failures, and schedule maintenance proactively. AI and ML tools also help in care for health monitoring systems and analysis of root causes. We will soon see certifications through simulations of numerous scenarios exercised on the system models.

Our solution accelerator for TEDAX- Tata Elxsi’s big data platform is being used to build system models and visualize the data. Tata Elxsi’s AI-based Video Analytics AIVA resolves complex scenarios in real-time.

ELE Times: How is Tata Elxsi enhancing aircraft production efficiency?

Jayaraj Rajapandian: The aerospace industry is picking up the pace in demand post-slowdown due to the COVID-19 pandemic. With the boost in demand, OEMs will need to enhance their production efficiency by tapping into advanced manufacturing technologies, adding cost-effective suppliers, and integrating product lifecycle management techniques. Technologies like 3D printing, robotics, digital twins, and automated assembly systems can enhance aircraft production.

Tata Elxsi designs and implements Industry 4.0 solutions, improving manufacturing performance. We are also working with OEMs in identifying suppliers to source raw materials, build-to-spec, and certify their products.

The post Tata Elxsi is Improving Aircraft Manufacturing Performance Through its Industry 4.0 solutions appeared first on ELE Times.

A professor at Missouri University of Science and Technology (Missouri S&T) has been awarded $875,000 from global mining group Rio Tinto for a two-year project researching new techniques to recover critical minerals in the waste by-products that come from extracting and refining copper...

Протокол засідання ректорату від 22 квітня 2024 року kpi ср, 04/24/2024 - 10:40

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Скелелази КПІ знову на висоті! Інформація КП вт, 04/23/2024 - 22:00

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Embedded World was rife with major hardware releases. Here are a few unique software packages designed to simplify the development experience.

КПІ відкриє медичний центр у кампусі medialab вт, 04/23/2024 - 18:51

Introduction

Electric vehicles (EVs) typically feature a large DC link capacitor (CDC LINK) to minimize voltage ripple at the input of the traction inverter. When powering up an EV, the purpose of precharging is to safely charge up CDC LINK before operating the vehicle. Charging CDC LINK up to the battery stack voltage (VBATT) prevents arcing on the contactor terminals, which can lead to catastrophic failures over time.

The conventional precharge method involves implementing a power resistor in series with the CDC LINK to create a resistor-capacitor (RC) network. However, as the total CDC LINK capacitance and VBATT increase, the required power dissipation grows exponentially. In this article, we’ll present a straightforward approach to designing an efficient, active pre-charge circuit using a spreadsheet calculator.

Understanding active precharge

While passive precharge employs a power resistor to create an RC circuit that charges the capacitor asymptotically, active precharge can employ a switching converter with a buck topology that uses hysteretic inductor current control to deliver a constant charge current to the capacitor (Figure 1).

Figure 1 The active precharge circuit where a buck converter uses a hysteretic inductor current control to deliver a constant charge current to the capacitor to enable the linear charge of the capacitor voltage (VCAP) up to the same voltage potential as the battery (VBATT). Source: Texas Instruments

This constant current enables linear charging of the capacitor voltage (VCAP) up to the same voltage potential as that of the battery. Figure 2 and Equation 1 characterize this linear behavior.

Figure 2 Active precharge linear behavior using a buck topology with hysteretic inductor current control. Source: Texas Instruments

The first step is to determine the required charge current (ICHARGE). ICHARGE is the quotient of the total DC link charge (QDC LINK) and the required precharge time (tCHARGE) shown in Equation 2.

QDC LINK is the product of CDC LINK and VBATT, as shown in Equation 3.

Calculator overview

This active hysteretic buck circuit has a floating ground potential riding on the switch node, so powering the control system requires an isolated bias supply. The calculator tool will ensure that the power consumption of this control circuitry stays within the sourcing capability of the isolated bias supply, or else the voltage will collapse.

The High-Voltage Solid-State Relay Active Precharge Reference Design from Texas Instruments (TI) introduces an active solution that enhances energy transfer efficiency and reduces practical charge time. TI’s TPSI3052-Q1 is a fully integrated isolated bias supply used in the active precharge reference design, which can source and supply up to 83 mW of power to the isolated secondary. Gate drive current, device quiescent currents, and resistor dividers are the primary contributors to power consumption. Equation 4 characterizes the gate drive power (PGATE DRIVE) as the product of the gate drive current (IGATE DRIVE) and gate drive voltage (VS GATE DRIVER) which is 15 V, in the case of the reference design.

Equation 5 characterizes gate drive current as the product of the metal-oxide semiconductor field-effect transistor (MOSFET) total gate charge (QG) and switching frequency (FSW).

Equation 6 expresses how FSW varies according to VCAP throughout the charging period, creating the upside-down parabola in the FSW versus VCAP curve in Figure 3. As shown in the Figure, the gate drive current peaks at the maximum switching frequency (FSW_MAX), which occurs when VCAP reaches half of VBATT. Equation 7 expresses the relationship between FSW_MAX, VBATT, inductance (L) and peak-to-peak inductor current (dI):

Figure 3 Calculator curve showing FSW versus VCAP and FSW LIMIT. Source: Texas Instruments

Using the calculator tool

The calculator prompts you to input various design parameters. The yellow cells are the required inputs while gray cells signify optional inputs. The default values in the gray cells reflect the parameters of the reference design. A user can change the gray cell values as needed. The white cells show the calculated values as outputs. A red triangle in the upper-right corner of a cell indicates an error; users will be able to see a pop-up text on how to fix them. The objective is to achieve a successful configuration with no red cells. This can be an iterative process where users can hover their mouse over each of the unit cells to read explanatory information.

Precharge system requirements

The first section of the calculator, shown in Figure 4, computes the required charge current
(ICHARGE REQUIRED) based on the VBATT, tCHARGE, and CDC LINK system parameters.

Figure 4 The required charge current (ICHARGE REQUIRED) based on the VBATT, tCHARGE, and CDC LINK system parameters. Source: Texas Instruments

Inductance and charge current programming

The section of the calculator shown in Figure 5 calculates the actual average charging current (ICHARGE) and FSW_MAX. The average inductor current essentially equates to ICHARGE where ICHARGE must be equal to or greater than ICHARGE REQUIRED, this was calculated in the previous section to meet the desired tCHARGE.

Be mindful of the relationship between L, dI, and FSW_MAX as expressed in Equation 7. L and dI are each inversely proportional to FSW, so it is important to select values that do not exceed the maximum switching frequency limit (FSW LIMIT). Your inductor selection should accommodate adequate root-mean-square current (IRMS > ICHARGE), saturation current (ISAT > IL PEAK), and voltage ratings, with enough headroom as a buffer for each.

Figure 5 Inductance and charge current programming parameters. Source: Texas Instruments

 Current sensing and comparator setpoints

The section of the calculator shown in Figure 6 calculates the bottom resistance (RB), top resistance (RT), and hysteresis resistance (RH) around the hysteresis circuit needed to meet the peak (IL PEAK) and valley (IL VALLEY) inductor current thresholds specified in the previous section. Input the current sense resistance (RSENSE) and RB. These are flexible and can be changed as needed. Make sure that the comparator supply voltage (VS COMPARATOR) is correct.

Figure 6 Section that calculates the bottom resistance (RB), top resistance (RT), and hysteresis resistance (RH) around the hysteresis circuit needed to meet the peak (IL PEAK) and valley (IL VALLEY) inductor current thresholds. Source: Texas Instruments

Bias supply and switching frequency limitations

The section of the calculator shown in Figure 7 calculates the power available for switching the MOSFET (PREMAINING FOR FET DRIVE), by first calculating the total power draw (PTOTAL) associated with the hysteresis circuit resistors (PCOMP. RESISTORS), the gate driver integrated circuit (IC) (PGATE DRIVER IC), and the comparator IC (PCOMPARATOR IC), and subtracting it from the maximum available power of the TPSI3052-Q1 (PMAX_ISOLATED BIAS SUPPLY). Input the MOSFET total gate charge (QG TOTAL), device quiescent currents (IS GATE DRIVER IC and ISUPPLY COMP IC), and gate driver IC supply voltage (VS GATE DRIVER IC). The tool uses these inputs to calculate FSW LIMIT displayed as a red line in Figure 3.

Figure 7 Isolated bias supply and switching frequency limitations parameters. Source: Texas Instruments

The calculator tool makes certain assumptions and do not account for factors such as comparator delays and power losses in both the MOSFET and the freewheeling diode. The tool assumes the use of rail-to-rail input and output comparators. Make sure to select a MOSFET with an appropriate voltage rating, RDSON, and parasitic capacitance parameters. Ensure the power loss in both the MOSFET and freewheeling diode are within acceptable limits. Finally, select a comparator with low offset and low hysteresis voltages with respect to the current sense peak and valley-level voltages. Simulating the circuit with the final calculator values ensures the intended operation.

Achieved the desired charge profile

Adopting an active hysteretic buck circuit significantly improves efficiency and reduces the size of the charging circuitry in high voltage DC-link capacitors found in EVs. This helps potentially lower the size, cost, and thermals of a precharge solution.

This article presents the design process to calculate the appropriate component values that help achieve the desired charge profile.

By embracing these techniques and tools, engineers can effectively improve the precharge functionality in EVs, leading to improved power management systems to meet the increasing demands of the automotive industry.

Tilden Chen works as an Applications Engineer for the Texas Instruments Solid State Relays team, where he provides product support and generates technical collateral to help win business opportunities. Tilden joined TI in 2021 after graduating from Iowa State University with a B.S. in Electrical Engineering. Outside of work, Tilden enjoys participating in Brazilian jiu-jitsu and shuffle dancing.

 Hrag Kasparian, who joined Texas Instruments over 10 years ago, currently serves as a power applications engineer, designing custom dc-dc switch-mode power supplies. Previously, he worked on development of battery packs, chargers, and electric vehicle (EV) battery management systems at a startup company in Silicon Valley. Hrag graduated from San Jose State University with a bachelor of science in electrical engineering.

Related Content

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• Power Tips #126: Hot plugging DC/DC converters safely
• Power Tips #125: How an opto-emulator improves reliability and transient response for isolated DC/DC converters
• Teardown: The nuances of variable-frequency drives

The post Power Tips #128: Designing a high voltage DC-link capacitor active precharge circuit appeared first on EDN.

Підсумки The BUP Student Conference 2024 «Changed circumstances and new threats for sustainability in the Baltic Sea Region» medialab вт, 04/23/2024 - 18:19

Compound Semiconductor Applications (CSA) Catapult in Newport, South Wales, UK and Malaysia-based SMD Semiconductor Sdn Bhd (a wholly owned entity of the Sarawak Government established in September 2022 under the Sarawak Research and Development Council Ordinance 2017) have signed a memorandum of understanding (MoU) that lays the foundation to work together in the design, prototyping and manufacturing of next-generation semiconductor and compound semiconductor chips in the automotive and space industries...

Безпека АЕС після Чорнобильської катастрофи та під час війни: спілкуємося з фахівцем Інформація КП вт, 04/23/2024 - 16:00

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