scholarly journals Circuit Techniques in GaN Technology for High-Temperature Environments

Electronics ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 42
Author(s):  
Ahmad Hassan ◽  
Jean-Paul Noël ◽  
Yvon Savaria ◽  
Mohamad Sawan
Keyword(s):  
High Temperature ◽  
Integrated Circuits ◽  
National Research Council ◽  
Logic Gates ◽  
Voltage Reference ◽  
Flip Flop ◽  
Wide Range ◽  
Circuit Techniques ◽  
First Time

As a wide bandgap semiconductor, Gallium Nitride (GaN) device proves itself as a suitable candidate to implement high temperature (HT) integrated circuits. GaN500 is a technology available from the National Research Council of Canada to serve RF applications. However, this technology has the potential to boost HT electronics to higher ranges of operating temperatures and to higher levels of integration. This paper summarizes the outcome of five years of research investigating the implementation of GaN500-based circuits to support HT applications such as aerospace missions and deep earth drilling. More than 15 integrated circuits were implemented and tested. We performed the HT characterization of passive elements integrated in GaN500 including resistors, capacitors, and inductors up to 600 °C. Moreover, we developed for the first time several digital circuits based on GaN500 technology, including logic gates (NOT, NAND, NOR), ring oscillators, D Flip-Flop, Delay circuits, and voltage reference circuits. The tested circuits are fabricated on a 4 mm × 4 mm chip to validate their functionality over a wide range of temperatures. The logic gates show functionality at HT over 400 °C, while the voltage reference circuits remain stable up to 550 °C.

scholarly journals Efficient and Compact SR-flip Flop Optical Memory Based Photonic Crystals Platform

2021 ◽  
Author(s):  
Amr Hassan ◽  
Nihal F. F. Areed ◽  
Salah S. A. Obayya ◽  
Hamdi El Mikati
Keyword(s):  
Integrated Circuits ◽  
Optical Memory ◽  
Logic Gates ◽  
Power Input ◽  
Small Dimension ◽  
Square Lattice ◽  
Optical Logic ◽  
Flip Flop ◽  
Compact Size ◽  
Multiple Devices

Abstract The paper presents a different type of designing methods and operational improvements of the optical logic memory SR-flip flop (SR-FF). The proposed optical memory SR-FF is based on two optical NOR logic gates which use two-dimension (2D) photonic crystal (PhC) with a square lattice of silicon (Si) dielectric rods. The structure has a switching time in only a few Picoseconds with little power input and very little power loss. The proposed optical memory SR-FF has a small dimension 38x22 μm2 which makes it one of the best optimized and most practical structures to be used in all photonic integrated circuits (PICs). The ultra-compact size enables the possibility of multiple devices to be embedded in a single PIC chip.

Robust True LDO Linear Voltage Regulator and Digitally Trimmable Buffered Precision Voltage Reference for High-Temperature, Low-Voltage Applications

2013 ◽  
Vol 2013 (HITEN) ◽  
pp. 000096-000103
Author(s):  
Yoann Dusé ◽  
Fabien Laplace ◽  
Nicolas Joubert ◽  
Xavier Montmayeur ◽  
Noureddine Zitouni ◽  
...  
Keyword(s):  
High Temperature ◽  
Temperature Coefficient ◽  
Low Voltage ◽  
Short Circuit ◽  
Silicon On Insulator ◽  
Voltage Regulator ◽  
Voltage Reference ◽  
Soft Start ◽  
Wide Range ◽  
Latch Up

We present in this paper two new products for high-temperature, low-voltage (2.8V to 5.5V) power management applications. The first product is an original implementation of a monolithic low dropout regulator (XTR70010), able to deliver up to 1A at 230°C with less than 1V of dropout. This new voltage regulator can source an output current level up to 1.5A. The regulated output voltage can be selected among 32 preset values from 0.5V to 3.6V in steps of 100mV, or it can be obtained with a pair of external resistors. The circuit integrates complex analog and digital control blocks providing state of the art features such as UVLO protection, chip enable control, soft start-up and soft shut-down, hiccup short-circuit protection, customer selectable thermal shut-down, input power supply protection, output overshoot remover and stability over an extremely wide range of load capacitances. The circuit offers a fair ±2% absolute accuracy and is guaranteed latch-up free. The second product is an advanced high-temperature, low-power, digitally trimmable voltage reference (XTR75020). Thanks to a custom, 1-wire serial interface, the absolute precision and the temperature coefficient can be adjusted in order to obtain an accuracy better than 0.5% with a temperature coefficient bellow ±20ppm/°C. On-chip OTP memory for trimming of absolute value and temperature coefficient makes the circuit extremely accurate and almost insensitive to drifts over time and temperature. The circuit features a class AB output buffer able to source or sink up to 5mA and remains stable with any load capacitance up to 50μF. The XTR75020 has nine preset possible output voltages. The source and sink short circuit current always remains bellow 25mA. The quiescent current consumption is 300μA typical at 230°C while the standby current is, in all cases, under 20μA. Both devices are designed on a latch-up free silicon-on-insulator process.

scholarly journals Polarimetry for Photonic Integrated Circuits

2019 ◽  
Vol 9 (15) ◽  
pp. 2987
Author(s):  
Moritz Baier ◽  
Axel Schoenau ◽  
Francisco M. Soares ◽  
Martin Schell
Keyword(s):  
Integrated Circuits ◽  
Photonic Integrated Circuits ◽  
The State ◽  
Polarization Dependence ◽  
Complete Picture ◽  
Wide Range ◽  
State Of Polarization ◽  
Matrix Yielding ◽  
Polarization Of Light

Photonic integrated circuits (PICs) play a key role in a wide range of applications. Very often, the performance of PICs depends strongly on the state of polarization of light. Classically, this is regarded as undesirable, but more and more applications emerge that make explicit use of polarization dependence. In either case, the characterization of the polarization properties of a PIC can be a nontrivial task. We present a way of characterizing PICs in terms of their full Müller matrix, yielding a complete picture of their polarization properties. The approach is demonstrated by carrying out measurements of fabricated PICs.

scholarly journals Sequential Logic Circuits Using Spatial Wavefunction Switched (SWS) FETs

2015 ◽  
Vol 24 (03n04) ◽  
pp. 1550011
Author(s):  
Neeraja Jagadeesan ◽  
B. Saman ◽  
M. Lingalugari ◽  
P. Gogna ◽  
F. Jain
Keyword(s):  
Integrated Circuits ◽  
Quantum Well ◽  
Logic Gates ◽  
Digital Integrated Circuits ◽  
Short Channel ◽  
Flip Flop ◽  
Coupled Channels ◽  
Threshold Voltages ◽  
Sequential Logic ◽  
Quantum Well Devices

The spatial wavefunction-switched field-effect transistor (SWSFET) is one of the promising quantum well devices that transfers electrons from one quantum well channel to the other channel based on the applied gate voltage. This eliminates the use of more transistors as we have coupled channels in the same device operating at different threshold voltages. This feature can be exploited in many digital integrated circuits thus reducing the count of transistors which translates to less die area. The simulations of basic sequential circuits like SR latch, D latch and flip flop are presented here using SWSFET based logic gates. The circuit model of a SWSFET was developed using Berkeley short channel IGFET model (BSIM 3).

scholarly journals Enzymic and structural characterization of nepenthesin, a unique member of a novel subfamily of aspartic proteinases

2004 ◽  
Vol 381 (1) ◽  
pp. 295-306 ◽  
Author(s):  
Senarath B. P. ATHAUDA ◽  
Koji MATSUMOTO ◽  
Sanath RAJAPAKSHE ◽  
Masayuki KURIBAYASHI ◽  
Masaki KOJIMA ◽  
...  
Keyword(s):  
Amino Acid ◽  
Computer Modelling ◽  
Structural Characteristics ◽  
Amino Acid Sequences ◽  
Cysteine Residues ◽  
Aspartic Proteinases ◽  
Protein Databases ◽  
Wide Range ◽  
First Time

Carnivorous plants are known to secrete acid proteinases to digest prey, mainly insects, for nitrogen uptake. In the present study, we have purified, for the first time, to homogeneity two acid proteinases (nepenthesins I and II) from the pitcher fluid of Nepenthes distillatoria (a pitcher-plant known locally as badura) and investigated their enzymic and structural characteristics. Both enzymes were optimally active at pH approx. 2.6 towards acid-denatured haemoglobin; the specificity of nepenthesin I towards oxidized insulin B chain appears to be similar, but slightly wider than those of other APs (aspartic proteinases). Among the enzymic properties, however, the most notable is their unusual stability: both enzymes were remarkably stable at or below 50 °C, especially nepenthesin I was extremely stable over a wide range of pH from 3 to 10 for over 30 days. This suggests an evolutionary adaptation of the enzymes to their specific habitat. We have also cloned the cDNAs and deduced the complete amino acid sequences of the precursors of nepenthesins I and II (437 and 438 residues respectively) from the pitcher tissue of N. gracilis. Although the corresponding mature enzymes (each 359 residues) are homologous with ordinary pepsin-type APs, both enzymes had a high content of cysteine residues (12 residues/molecule), which are assumed to form six unique disulphide bonds as suggested by computer modelling and are supposed to contribute towards the remarkable stability of nepenthesins. Moreover, the amino acid sequence identity of nepenthesins with ordinary APs, including plant vacuolar APs, is remarkably low (approx. 20%), and phylogenetic comparison shows that nepenthesins are distantly related to them to form a novel subfamily of APs with a high content of cysteine residues and a characteristic insertion, named ‘the nepenthesin-type AP-specific insertion’, that includes a large number of novel, orthologous plant APs emerging in the gene/protein databases.

scholarly journals First Apocarotenoids Profiling of Four Microalgae Strains

Antioxidants ◽  
2019 ◽  
Vol 8 (7) ◽  
pp. 209 ◽  
Author(s):  
Mariosimone Zoccali ◽  
Daniele Giuffrida ◽  
Fabio Salafia ◽  
Carmen Socaciu ◽  
Kari Skjånes ◽  
...  
Keyword(s):  
Supercritical Fluid ◽  
Fatty Acid Esters ◽  
Nannochloropsis Gaditana ◽  
Tetraselmis Chuii ◽  
Chromatography Tandem Mass Spectrometry ◽  
Wide Range ◽  
First Time ◽  
Chlamydomonas Sp ◽  
Acid Esters

Both enzymatic or oxidative carotenoids cleavages can often occur in nature and produce a wide range of bioactive apocarotenoids. Considering that no detailed information is available in the literature regarding the occurrence of apocarotenoids in microalgae species, the aim of this study was to study the extraction and characterization of apocarotenoids in four different microalgae strains: Chlamydomonas sp. CCMP 2294, Tetraselmis chuii SAG 8-6, Nannochloropsis gaditana CCMP 526, and Chlorella sorokiniana NIVA-CHL 176. This was done for the first time using an online method coupling supercritical fluid extraction and supercritical fluid chromatography tandem mass spectrometry. A total of 29 different apocarotenoids, including various apocarotenoid fatty acid esters, were detected: apo-12’-zeaxanthinal, β-apo-12’-carotenal, apo-12-luteinal, and apo-12’-violaxanthal. These were detected in all the investigated strains together with the two apocarotenoid esters, apo-10’-zeaxanthinal-C4:0 and apo-8’-zeaxanthinal-C8:0. The overall extraction and detection time for the apocarotenoids was less than 10 min, including apocarotenoids esters, with an overall analysis time of less than 20 min. Moreover, preliminary quantitative data showed that the β-apo-8’-carotenal content was around 0.8% and 2.4% of the parent carotenoid, in the C. sorokiniana and T. chuii strains, respectively. This methodology could be applied as a selective and efficient method for the apocarotenoids detection.

scholarly journals Metal-Semiconductor-Metal GeSn Photodetectors on Silicon for Short-Wave Infrared Applications

Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 795
Author(s):  
Soumava Ghosh ◽  
Kuan-Chih Lin ◽  
Cheng-Hsun Tsai ◽  
Harshvardhan Kumar ◽  
Qimiao Chen ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Collection Efficiency ◽  
Short Wave ◽  
Carrier Generation ◽  
Optical Components ◽  
Metal Semiconductor Metal ◽  
Wide Range ◽  
Short Wave Infrared ◽  
Planar Fabrication

Metal-semiconductor-metal photodetectors (MSM PDs) are effective for monolithic integration with other optical components of the photonic circuits because of the planar fabrication technique. In this article, we present the design, growth, and characterization of GeSn MSM PDs that are suitable for photonic integrated circuits. The introduction of 4% Sn in the GeSn active region also reduces the direct bandgap and shows a redshift in the optical responsivity spectra, which can extend up to 1800 nm wavelength, which means it can cover the entire telecommunication bands. The spectral responsivity increases with an increase in bias voltage caused by the high electric field, which enhances the carrier generation rate and the carrier collection efficiency. Therefore, the GeSn MSM PDs can be a suitable device for a wide range of short-wave infrared (SWIR) applications.

Digital and Analogue Integrated Circuits in Silicon Carbide for High Temperature Operation

2012 ◽  
Vol 2012 (HITEC) ◽  
pp. 000373-000377 ◽  
Author(s):  
E.P Ramsay ◽  
D.T. Clark ◽  
J.D. Cormack ◽  
A.E. Murphy ◽  
D.A Smith ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Integrated Circuits ◽  
Integrated Circuit ◽  
Nand Gate ◽  
Cmos Process ◽  
Flip Flop ◽  
Aero Engines ◽  
Simple Logic ◽  
High Temperature Operation

A need for high temperature integrated circuits is emerging in a number of application areas. As Silicon Carbide power discrete devices become more widely available, there is a growing need for control ICs capable of operating at the same temperatures and mounted on the same modules. Also, the use of high temperature sensors, in, for example, aero engines and in deep hydrocarbon and geothermal drilling applications results in a demand for high temperature sensor interface ICs. This paper presents new results on a range of simple logic and analogue circuits fabricated on a developing Silicon Carbide CMOS process which is intended for mixed signal integrated circuit applications such as those above. A small family of logic circuits, pin compatible with the 74xx series TTL logic parts, has been designed, fabricated and tested and includes, for example, a Quad Nand gate and a Dual D-type flip-flop. These have been found to be functional from room temperature up to 400°C. Analogue blocks have been investigated with a view to using switched capacitor or autozero techniques to compensate for temperature and time induced drifts, allowing very high temperature operation.

4H-SiC Digital Logic Circuitry Based on P+ Implanted Isolation Walls MESFET Technology

2013 ◽  
Vol 740-742 ◽  
pp. 1048-1051 ◽  
Author(s):  
Mihaela Alexandru ◽  
Viorel Banu ◽  
Phillippe Godignon ◽  
Miguel Vellvehi ◽  
José Millan
Keyword(s):  
High Temperature ◽  
Integrated Circuits ◽  
Unit Area ◽  
Logic Gates ◽  
Wafer Surface ◽  
Intelligent Sensors ◽  
Complex Design ◽  
Integration Density ◽  
Poly Type ◽  
Increasing Demand

The design and development of SiC integrated circuits (ICs) nowadays is a necessity due to the increasing demand for high temperature intelligent power applications and intelligent sensors. Due to the superior electrical, mechanical and chemical proprieties of 4H-SiC poly-type, 4H-SiC MESFET transistor is a good compromise for ICs on SiC able to work at higher temperatures (HT) than on Si. This paper presents new experimental results of approaching embedded logic gates with SiC MESFETs and resistors, built in junction-isolated tubs. The P+ implantation isolation technology offers important perspectives regarding the integration density of devices per unit area and wafer surface, being able to use far more complex design geometry for modeling ICs on SiC.

Analysis of Natural Toxins by Liquid Chromatography-Chemiluminescence Nitrogen Detection and Application to the Preparation of Certified Reference Materials

2016 ◽  
Vol 99 (5) ◽  
pp. 1173-1184 ◽  
Author(s):  
Krista Thomas ◽  
Dominik Wechsler ◽  
Yi-Min Chen ◽  
Sheila Crain ◽  
Michael A Quilliam
Keyword(s):  
Reference Materials ◽  
Limit Of Detection ◽  
Certified Reference Materials ◽  
National Research Council ◽  
Complementary Method ◽  
Routine Monitoring ◽  
Wide Range ◽  
Measurement Results ◽  
Calibration Solution

Abstract The implementation of instrumental analytical methods such as LC-MS for routine monitoring of toxins requires the availability of accurate calibration standards. This is a challenge because many toxins are rare, expensive, dangerous to handle, and/or unstable, and simple gravimetric procedures are not reliable for establishing accurate concentrations in solution. NMR has served as one method of qualitative and quantitative characterization of toxin calibration solution Certified Reference Materials (CRMs). LC with chemiluminescence N detection (LC-CLND) was selected as a complementary method for comprehensive characterization of CRMs because it provides a molar response to N. Here we report on our investigation of LC-CLND as a method suitable for quantitative analysis of nitrogenous toxins. It was demonstrated that a wide range of toxins could be analyzed quantitatively by LC-CLND. Furthermore, equimolar responses among diverse structures were established and it was shown that a single high-purity standard such as caffeine could be used for instrument calibration. The limit of detection was approximately 0.6 ng N. Measurement of several of Canada's National Research Council toxin CRMs with caffeine as the calibrant showed precision averaging 2% RSD and accuracy ranging from 97 to 102%. Application of LC-CLND to the production of calibration solution CRMs and the establishment of traceability of measurement results are presented.

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