Semiconductors & ICs

Metal-Assisted Chemical Etching

University of Illinois researchers have developed a method to chemically etch patterned arrays in the semiconductor gallium arsenide - used in solar cells, lasers, light-emitting diodes (LEDs), field effect transistors (FETs), capacitors, and sensors.

Posted in: News, News, Renewable Energy, Solar Power, LEDs, Metals, Semiconductors & ICs

Composite Metamaterial for Solar Tech

A Northwestern University research team has developed a new material that absorbs a wide range of wavelengths and could lead to more efficient and less expensive solar technology. The researchers used two unconventional materials – metal and silicon oxide – to create thin but complex, trapezoid-shaped metal gratings on the nanoscale that can trap a wider range of visible light.

Posted in: GDM, News, News, Energy, Energy Efficiency, Renewable Energy, Solar Power, Materials, Metals, Semiconductors & ICs

MOSFET Switching Circuit Protects Shape Memory Alloy Actuators

A small-footprint, full surface-mount-component printed circuit board employs MOSFET (metal-oxide-semi-conductor field-effect transistor) power switches to switch high currents from any input power supply from 3 to 30 V.

Posted in: Briefs, TSP, Semiconductors & ICs, Integrated circuits, Switches, Semiconductors

Optimized FPGA Implementation of Multi-Rate FIR Filters Through Thread Decomposition

This technique is used in design automation and in digital circuit design.

Multi-rate finite impulse response (MRFIR) filters are among the essential signal-processing components in space-borne instruments where finite impulse response filters are often used to minimize nonlinear group delay and finite-precision effects. Cascaded (multi-stage) designs of MRFIR filters are further used for large rate change ratio in order to lower the required throughput, while simultaneously achieving comparable or better performance than single-stage designs. Traditional representation and implementation of MRFIR employ polyphase decomposition of the original filter structure, whose main purpose is to compute only the needed output at the lowest possible sampling rate.

Posted in: Briefs, Semiconductors & ICs, Design processes, Integrated circuits, Automation

Circuit for Communication Over Power Lines

This technique can be used in vehicle sensors, building sensors, and other industrial control applications.

Many distributed systems share common sensors and instruments along with a common power line supplying current to the system. A communication technique and circuit has been developed that allows for the simple inclusion of an instrument, sensor, or actuator node within any system containing a common power bus. Wherever power is available, a node can be added, which can then draw power for itself, its associated sensors, and actuators from the power bus all while communicating with other nodes on the power bus.

Posted in: Briefs, TSP, Semiconductors & ICs, Integrated circuits, Sensors and actuators, Telecommunications systems

High-Voltage-Input Level Translator Using Standard CMOS

High-voltage input circuitry would be combined with standard low-voltage CMOS circuitry.

A proposed integrated circuit would translate (1) a pair of input signals having a low differential potential and a possibly high common-mode potential into (2) a pair of output signals having the same low differential potential and a low common-mode potential. As used here, “low” and “high” refer to potentials that are, respectively, below or above the nominal supply potential (3.3 V) at which standard complementary metal oxide/semiconductor (CMOS) integrated circuits are designed to operate. The input common-mode potential could lie between 0 and 10 V; the output common-mode potential would be 2 V. This translation would make it possible to process the pair of signals by use of standard 3.3-V CMOS analog and/or mixed-signal (analog and digital) circuitry on the same integrated-circuit chip. A schematic of the circuit is shown in the figure.

Posted in: Briefs, TSP, Semiconductors & ICs, Integrated circuits, Semiconductors

Small Microprocessor for ASIC or FPGA Implementation

A small microprocessor, suitable for use in applications in which high reliability is required, was designed to be implemented in either an application-specific integrated circuit (ASIC) or a field-programmable gate array (FPGA). The design is based on commercial microprocessor architecture, making it possible to use available software development tools and thereby to implement the microprocessor at relatively low cost. The design features enhancements, including trapping during execution of illegal instructions. The internal structure of the design yields relatively high performance, with a significant decrease, relative to other microprocessors that perform the same functions, in the number of microcycles needed to execute macroinstructions.

Posted in: Briefs, TSP, Semiconductors & ICs, Architecture, Computer software and hardware, Integrated circuits, Semiconductors

Source-Coupled, N-Channel, JFET-Based Digital Logic Gate Structure Using Resistive Level Shifters

A circuit topography is used to create usable, digital logic gates using N (negatively doped) channel junction field effect transistors (JFETs), load resistors, level shifting resistors, and supply rails whose values are based on the DC parametric distributions of these JFETs. This method has direct application to the current state-of-the-art in high-temperature (300 to 500 °C and higher) silicon carbide (SiC) device production, and defines an adaptation to the logic gate described in U.S. Patent 7,688,117 in that, by removing the level shifter from the output of the gate structure described in the patent (and applying it to the input of the same gate), a source-coupled gate topography is created. This structure allows for the construction AND/OR (sum of products) arrays that use far fewer transistors and resistors than the same array as constructed from the gates described in the aforementioned patent. This plays a central role when large multiplexer constructs are necessary; for example, as in the construction of memory.

Posted in: Briefs, TSP, Semiconductors & ICs, Electronic equipment, Transistors, Semiconductors

Monitoring Digital Closed-Loop Feedback Systems

Designed-in test circuitry enables determination of performance margins and performance trends.

A technique of monitoring digital closed-loop feedback systems has been conceived. The basic idea is to obtain information on the performances of closed-loop feedback circuits in such systems to aid in the determination of the functionality and integrity of the circuits and of performance margins.

Posted in: Briefs, TSP, Semiconductors & ICs, Integrated circuits, Semiconductors, Performance tests

Semiconductor Laser Technology Chosen for Space LIDAR

Single-frequency semiconductor laserRedfern Integrated Optics (RIO)Santa Clara,

NASA has chosen Redfern Integrated Optics to further develop a single-frequency, narrow-linewidth semiconductor laser suitable for spaceflight operation. RIO’s external-cavity semiconductor laser technology is based on the hybrid integration of an indium phosphide (InP) gain chip and a planar lightwave circuit (PLC) with Bragg gratings. Packaged in a standard 14-pin compact “butterfly” package, the laser is characterized by a single-frequency output in the 1550-nm spectral region with a linewidth less than 2 kHz, low phase noise, low relative intensity noise (RIN), and high immunity to vibrations in a wide range of operating temperatures.

Posted in: Application Briefs, Lasers & Laser Systems, Semiconductors & ICs, Lidar, Suppliers, Semiconductors

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