Auto-Balancing Series-Stacked Input DC-DC Converter

ADC-DC converter that can operate from a high input voltage is needed for future high-power space applications. However, the selection of space-qualified, high-voltage transistors and filter capacitors for such a converter are very limited. The available high-voltage components have lower performance than lower-voltage components. One possible solution to this problem is connecting in series the inputs of multiple converters to lower the input voltage at the individual converter inputs. However, because of component tolerances, performance degradation, and transient events, this can result in an unbalanced voltage distribution throughout the various inputs. Excessive voltage on any of the stacked converters can damage components and cause a catastrophic failure. A circuit that could inherently balance the voltage between the inputs of multiple low-voltage DCDC converters would have better performance and reliability.

Posted in: Briefs, Board-Level Electronics, Electronics & Computers, Power Management, Capacitors, Integrated circuits, Switches, Transistors, Capacitors, Integrated circuits, Switches, Transistors, Performance upgrades, Spacecraft
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Larger-Area Integrated Electrical Metallization Dielectric Structures with Stress-Managed Unit Cells for Extreme- Environment Semiconductor Electronics Chips

The use of patterned multiple layers of thin films of metal and dielectric to form integrated circuit interconnections of transistors and/or form on-chip circuit capacitors is well known to those skilled in the art of semiconductor microelectronic fabrication. Because differing layers of thin film materials have different physical and thermal expansion properties, it is also well known that stress is inherently present in these multilayer film structures on a microelectronic chip. The amount of stress changes with temperature and as a function of lateral feature size/area across the chip. When stress anywhere within a patterned metal film feature becomes critically large (i.e., the “yield stress” is exceeded), the metal film can physically crack, buckle, or delaminate from other layers, which usually damages/fails the intended electrical operation of the microelectronic circuit.

Posted in: Briefs, Electronics & Computers, Failure modes and effects analysis, Capacitors, Integrated circuits, Capacitors, Integrated circuits, Fabrication, Semiconductors
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Performance Characteristics of Digital Frequency Discriminators

Digital frequency discriminators are key components of instantaneous frequency measurement (IFM) receiver systems as well as many other complex electronic warfare (EW) systems. However, to obtain optimum results it is essential to match DFD performance levels to a specific application. DFDs are integral components of IFM receiver systems; they may also be imbedded into a wide range of military systems such as radar warning receivers (RWRs), electronic countermeasures (ECM) systems, and electronic support measures (ESM) platforms, where they help provide instantaneous frequency measurement capability.

Posted in: White Papers, White Papers, Electronics & Computers
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High-Speed Switched Serial Fabrics Improve System Design

Well into its third decade of widespread deployment, VME adopted the new VXS gigabit serial interface, clearly representing the most significant leap in backplane data transfer rates throughout its entire history. Because VXS delivered such a dramatic improvement in embedded system performance, the use of gigabit serial technology was extended to create VPX. The OpenVPX initiative followed shortly thereafter, as risk-averse government agencies mandated the need for industry-wide standards. The hallmark of any successful standard is that it continues to evolve with technology, and none offers a better example than VME’s evolution to VXS and VPX.

Posted in: White Papers, White Papers, Electronics & Computers
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High-Speed Real Time Recording Systems

In today’s world of high-speed A/D converters operating in the gigahertz range, real-time signal recording has become a challenging task that requires specialized hardware and intelligent application software. When designing a real-time recorder capable of streaming sustained data to disk at rates of up to 5 GB/sec and higher, the system developer has to consider the limitations presented by the recorder’s operating and file systems, the limitations of disk drive technology, the hardware interfaces, and the RAID controller technology.

Posted in: White Papers, White Papers, Electronics & Computers
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Putting FPGAs to Work in Software Radio Systems

FPGAs have become an increasingly important resource for software radio systems. Programmable logic technology now offers significant advantages for implementing software radio functions such as DDCs (Digital Downconverters). Over the past few years, the functions associated with DDCs have seen a shift from being delivered in ASICs (Application-Specific ICs) to operating as IP (Intellectual Property) in FPGAs.

Posted in: White Papers, White Papers, Electronics & Computers, Semiconductors & ICs
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Critical Techniques for High-Speed A/Ds In Real-Time Systems Handbook

To help define the meaning of “high-speed A/D” used in this handbook, we will be focusing primarily on A/D converters with sampling rates higher than 100 MHz. We will review sampling techniques, FPGA technology and we will present the latest Pentek high-speed A/D products and applications based on them.

Posted in: White Papers, White Papers, Electronics & Computers
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Software-Defined Radio Handbook

SDR (Software-Defined Radio) has revolutionized electronic systems for a variety of applications including communications, data acquisition and signal processing.This handbook shows how DDCs (Digital Downconverters) and DUCs (Digital Upconverters), the fundamental building blocks of SDR, can replace legacy analog receiver and transmitter designs while offering significant benefits in performance, density and cost.

Posted in: White Papers, White Papers, Electronics & Computers
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Putting VPX and Open VPX to Work

Before the advent of OpenVPX, designers of embedded systems took advantage of the extreme connectivity offered by VPX (VITA 46), but were faced with a virtually unlimited number of possible implementations. Specific choices for the control and data channel assignments for each slot, the backplane connectivity, and serial fabrics were often made somewhat arbitrarily to suit the particular needs of the current system. Although following the general framework of VITA 46, each system tended to be so unique, that the boards and backplanes designed for one system were seldom usable in other systems, even from the same vendor.

Posted in: White Papers, White Papers, Electronics & Computers
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Is nine hours a day too much "screen time?"

This week's Question: A recent study from Common Sense Media found that parents spend more than nine hours (9:22) a day with screen media, with the vast majority of that time being spent with personal screen media (7:43) and only a little more than 90 minutes devoted to work screen media. Most parents surveyed (78 percent) believe they are good media-use role models for their kids.

What do you think? Is nine hours a day too much "screen time?"

Posted in: Question of the Week, Computers, Electronics, Electronics & Computers
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