Browse Topic: Transistors

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Smart Molecules Act as Computer TransistorsTBMG-4597706/01/2022
Researchers have discovered a single-molecule switch that can act like a transistor and store binary information such as the 1s and 0s used in classical computing. The molecule is around five square nanometers in size — more than one billion of them would fit onto the cross-section of a human hair. The researchers believe that molecules like the ones they have discovered could offer information density of around 250 terabits per square inch, which is around 100 times the storage density of current hard drives.
Graphene “Nano-Origami” Creates Tiny MicrochipsTBMG-3960408/01/2021
Tiny microchips can be made from graphene and other two-dimensional (2D) materials using a form of “nano-origami.” By creating kinks in the structure of graphene, researchers made the nanomaterial behave like a transistor and showed that when a strip of graphene is crinkled in this way, it can behave like a microchip that is around 100 times smaller than conventional microchips.
Radiation Effects on Electronics in Aligned Carbon Nanotube Technology (RadCNT)21AERP02_0702/01/2021
Characterizing the fundamental mechanisms and charge transport phenomena governing the interactions between ionizing and non-ionizing radiation with carbon-based (nanotube and graphene) field-effect transistors (FETs) devices and integrated circuits (ICs). Defense Threat Reduction Agency, Fort Belvoir, Virginia The main objective of the RadCNT program was the characterization of fundamental mechanisms and charge transport phenomena governing the interactions between ionizing and nonionizing radiation with carbon-based (nanotube and graphene) field-effect transistors (FETs) devices and integrated circuits (ICs). This effort was supported through the fabrication of aligned single-walled carbon nanotubes (SWCNT) FETs at the University of Southern California's (USC) Nanotechnology Research Laboratory and through a collaboration with the Naval Research Laboratories (NRL) for radiation testing and expertise in radiation effects characterization. The RadCNT program concentrated on
Solid-State Sensor for Detection and Characterization of Electric FieldsTBMG-3799011/01/2020
NASA’s Langley Research Center has developed a solid-state integrated circuit based on a field effect transistor (FET). Called ergFET, the sensor characterizes the electronic properties of materials, allowing for detection of items like baggage, wiring, and liquids, and can even be used for medical imaging such as remote EKG.
Single-Atom TransistorsTBMG-3722307/01/2020
Transistors consisting only of several-atom clusters or even single atoms could become the building blocks of a new generation of computers with unparalleled memory and processing power. But to realize the full potential of these tiny transistors — miniature electrical on-off switches — researchers must find a way to make many copies of these difficult-to-fabricate components.
Flexible, Powerful, Fast Bioelectronic DevicesTBMG-3713106/01/2020
Researchers are working to use unique properties of materials to develop novel electronic devices that allow efficient interaction with biological substrates — specifically neural networks and the brain.
Process Enables Manufacturing of Stretchy ElectronicsTBMG-3686505/01/2020
All electronic devices feature a hard computer chip, covered in many transistors and other semiconducting elements. Because computer chips are rigid, the electronic devices they power — such as smartphones, laptops, watches, and televisions — are similarly inflexible. A process was developed for manufacturing flexible electronics with multiple functionalities in a cost-effective way.
Electric Nanoscale Device Sees Through WallsTBMG-3684105/01/2020
Researchers have developed a nanodevice that operates more than 10 times faster than today’s fastest transistors and about 100 times faster than the transistors on most computers. The device generates high-power terahertz waves, which are notoriously difficult to produce and are useful in a variety of applications ranging from imaging and sensing to high-speed wireless communications.
Transistors Both Process and Store InformationTBMG-3596002/01/2020
A computer chip can process and store information using two different devices. If these devices could be combined into one or put next to each other, there would be more space on a chip, making it faster and more powerful. Engineers have developed a way that the millions of tiny switches used to process information (transistors) could also store that information as one device.
Software-Defined Analog Filters: A Paradigm Shift in Radio Filter Performance and CapabilityTBMG-3566512/01/2019
Among the most abundant components in all wireless system designs, analog RF filters are used to block interference from various internal and external sources. Limited spectrum divided among an ever-increasing number of users is further driving the need for these ubiquitous but in some ways anachronistic devices. Currently, interference is quite common among cellular base stations, satellite systems, radar installations, and other types of access and backhaul communications systems. Traditional filters are unable to cope with the requirements; in many cases, most often due to insufficient guard bandf. For example, in some international locales, LTE base stations and satellite receivers share the L-band frequencies. At around 3.5 GHz, 5G operators, CBRS radios, and military radars are trying to co-exist. To address this in-band interference, a new, tunable filtering technology is entering the marketplace, uniquely blending the best of both analog and digital technologies.
Method Makes Transistors and Electronic Devices from ThreadTBMG-3546711/01/2019
A transistor has been made from linen thread, enabling the creation of electronic devices made entirely of thin threads that could be woven into fabric, worn on the skin, or implanted surgically for diagnostic monitoring. The flexible electronic devices could enable a range of applications that conform to different shapes and allow free movement without compromising function.
Ultrathin Transistors for Faster Computer ChipsTBMG-3528310/01/2019
For decades, microchip transistors have become smaller, faster, and cheaper; however, miniaturization has reached a natural limit, as completely new problems arise when a length scale of only a few nanometers is approached.
Graphene Field Effect Transistors for Radiation Detection (GFET-RS)TBMG-3514809/01/2019
NASA Goddard Space Flight Center developed novel transistor technology based on a single graphene layer coupled to a radiation absorber substrate. Unlike conventional charge-sensing detectors, the GFET-RS utilizes the sensitive dependence of graphene conductance on local change of the electric field, which can be induced by interaction of radiation with the underlying absorber substrate.
Ultra-Clean Fabrication Platform for 2D TransistorsTBMG-3512909/01/2019
Recently discovered two-dimensional (2D) materials with superlative properties have the potential to advance semiconductors but creating 2D devices with both good electrical contacts and stable performance has proved challenging.
Technology Produces Unclonable Digital Fingerprints for Internet of Things DevicesTBMG-3493208/01/2019
Researchers have created technology that is 10 times more reliable than current methods of producing unclonable digital fingerprints that can be used to authenticate devices linked to the Internet of Things (IoT).
Direct-Write Quantum Calligraphy in Monolayer SemiconductorsTBMG-3462106/01/2019
In contrast with conventional light-emitting diodes (LEDs) that emit billions of photons simultaneously to form a steady stream of light, a single photon emitter (SPE) generates exactly one photon on demand, with each photon indistinguishable from another. These characteristics are essential for photon-based quantum technologies under development. In addition, such capabilities should be realized in a material platform that enables precise, repeatable placement of SPEs in a fully scalable fashion compatible with existing semiconductor chip manufacturing.
High-Performance, Current-Steering Digital-to-Analog ConverterTBMG-3439505/01/2019
A current-steering digital-to-analog converter (DAC) was developed that achieves improved switching times (up to 75% faster) in high-speed (gigahertz), high-resolution (8-14 bits) applications resulting in improvement of spurious free dynamic range (SFDR).
Microfabrication Technique Modifies Semiconductor Material Atom-by-AtomTBMG-3390503/01/2019
To keep up with Moore's Law — an observation made in the 1960s that the number of transistors on an integrated circuit doubles about every two years — researchers are finding ways to cram as many transistors as possible onto microchips. The newest trend is 3D transistors that stand vertically, like fins, and measure about 7 nanometers across — tens of thousands of times thinner than a human hair. Tens of billions of these transistors can fit on a single microchip, which is about the size of a fingernail.
Gated Chopper Integrator (GCI)TBMG-3339212/01/2018
Microvolt-level signals require gains of at least a thousand. Offsets and noise in the amplifier chain will be amplified by the same amount, which can saturate the amplifier or swamp the signal so it is not resolvable. Other methods use chopping and/or autozero techniques to lower the offset and noise. The key disadvantages of these methods are they require filters before and/or after demodulation of the amplified signal and delay equalization to account for the delay through the amplifier(s) prior to the demodulator. The gain of these circuits is generally limited to fixed values determined by resistors. These methods are also susceptible to transient noise associated with the switching action of the modulator.
One-Dimensional Material with High Current DensityTBMG-3323511/01/2018
Current density is the amount of electrical current per cross-sectional area at a given point. As transistors in integrated circuits become smaller and smaller, they need higher and higher current densities to perform at the desired level. Most conventional electrical conductors, such as copper, tend to break due to overheating or other factors at high current densities, presenting a barrier to creating increasingly small components.
Efficient Semiconductor Material for Thermal ManagementTBMG-3311410/01/2018
Computer processors have continued to shrink down to nanometer sizes where there can be billions of transistors on a single chip. This phenomenon is described under Moore's Law, which predicts that the number of transistors on a chip will double about every two years. Each generation of smaller chips helps make computers faster, more powerful, and able to do more work. But that means they're generating more heat.
Faster, More Efficient Information ProcessingTBMG-3286009/01/2018
For decades, computer chips have been shrinking thanks to a steady stream of technological improvements in processing density. Experts have, however, been warning that we'll soon reach the end of the trend known as Moore's Law, in which the number of transistors per square inch on integrated circuits doubles every year. In order to continue improving chip performance, either the material the transistors are made of — from silicon, to carbon nanotubes or graphene — or how current materials store and process information would need to change.
Merging Antenna and Electronics Boosts Energy and Spectrum EfficiencyTBMG-3291009/01/2018
By integrating the design of antennas and electronics, researchers from the Georgia Institute of Technology have boosted the energy and spectrum efficiency for a new class of millimeter-wave transmitters, allowing improved modulation and reduced generation of waste heat.
Merging Antenna and Electronics Boosts Energy and Spectrum Efficiency18AERP09_0609/01/2018
By integrating the design of antennas and electronics, researchers from the Georgia Institute of Technology have boosted the energy and spectrum efficiency for a new class of millimeter-wave transmitters, allowing improved modulation and reduced generation of waste heat. The new co-design technique - achieved through research sponsored by the U.S. Army Research Laboratory and Intel Corp. - allows simultaneous optimization of the millimeter-wave antennas and electronics. The hybrid devices use conventional materials and integrated circuit (IC) technology, meaning no changes would be required to manufacture and package them. The co-design scheme allows fabrication of multiple transmitters and receivers on the same IC chip or the same package, potentially enabling multiple-input-multiple-output (MIMO) systems as well as boosting data rates and link diversity.
Toon, John
Material Brings Optical Communication onto Silicon ChipsTBMG-3249808/01/2018
An increase in computing performance has been achieved by squeezing ever more transistors into a tighter space on microchips. This downsizing has also meant packing the wiring within microprocessors ever more tightly together, leading to effects such as signal leakage between components, which can slow down communication between different parts of the chip. This delay, known as the “interconnect bottleneck,” is becoming an increasing problem in high-speed computing systems.
Advances in Spintronic DevicesTBMG-3250308/01/2018
Spintronic devices promise to solve major problems in today's computers, which use massive amounts of electricity to generate heat. This requires expending even more energy for cooling. By contrast, spintronic devices generate little heat and use relatively minuscule amounts of electricity. Spintronic computers would require no energy to maintain data in memory. They would also start instantly and have the potential to be far more powerful than today's computers.
Integrating Optical Components into Existing Chip DesignsTBMG-2905606/01/2018
Moving from electrical communication to optical communication is attractive to chip manufacturers because it could significantly increase chips’ speed and reduce power consumption, an advantage that will grow in importance as chips’ transistor count continues to rise.
Transistor Material Provides Additional Computing Degrees of FreedomTBMG-2902806/01/2018
For several decades, improvements in conventional transistor materials have been sufficient to sustain Moore’s Law — the historical pattern of microchip manufacturers packing more transistors (and thus more information storage and handling capacity) into a given volume of silicon. Today, however, chipmakers are concerned that they might soon reach the fundamental limits of conventional materials. If they cannot continue to pack more transistors into smaller spaces, they worry that Moore’s Law would break down, preventing future circuits from becoming smaller and more powerful than their predecessors. Researchers worldwide are seeking new materials that can compute in smaller spaces, primarily by taking advantage of the additional degrees of freedom that the materials offer — using a material’s unique properties to perform more computations in the same space.
Method of Fabricating Ultra-Short-Gate-Length Thin-Film Transistors Using Optical LithographyTBMG-2831002/01/2018
The speed of thin-film transistors (TFTs) relates directly to their gate length, which must be kept as short as possible to lower electron transport time between electrodes, and improve its high-frequency response characteristics. Since current density is proportional to W/L, where W is the gate width and L is the gate length, reduced gate length improves device current capability. Photolithography, which is the main technology used in defining electrode dimensions for TFTs, is limited in scope to fabrication line widths larger than 1 micrometer.
Silicon Carbide High-Voltage SwitchTBMG-2818001/01/2018
High-voltage wide bandgap (WBG) semiconductor devices like 15-kV silicon carbide (SiC) MOSFETs have attracted attention because of potential applications in high-voltage and high-frequency power converters. These devices, however, are not commercially available, and their high cost due to expensive material growth and fabrication may limit their widespread adoption in the future.
Flexible, Printable Electronics for Sensor ArraysTBMG-2778911/01/2017
Printable electronics — flexible circuitry that is deposited on some type of plastic substrate — has been a major area of research for decades. But the ability to print the substrate itself greatly increases the range of devices the technique can yield.
Reconfigurable Chaos-Based MicrochipsTBMG-2650903/01/2017
Researchers at North Carolina State University have developed nonlinear chaos-based integrated circuits that enable computer chips to perform multiple functions with fewer transistors. These integrated circuits can be manufactured with off-the-shelf fabrication processes, and could lead to novel computer architectures that do more with less circuitry and fewer transistors.
Material Combination Enables Transistor Gate Length of 1 NanometerTBMG-2652503/01/2017
The laws of physics have set a 5-nanometer threshold on the size of transistor gates among conventional semiconductors, about one-quarter the size of high-end, 20-nanometer-gate transistors now on the market. Researchers from the Department of Energy's Lawrence Berkeley National Laboratory have created a transistor with a working 1-nanometer gate.
Aerospace & Defense Technology: February 201717AERP0202/02/2017
Open Standard Middleware Enables New HPEC Solutions Cooling Your Embedded System What Can Your Open Standard Architecture Handle? Evaluating Key Certification Aspects of Multicore Platforms for Safety Critical Avionics Applications Simulating and Analyzing Flow for an Air-to-Air Refueling System The Ins and Outs of Spaceflight Passive Components and Assemblies Development of High Quality 4H-SiC Thick Epitaxy for Reliable High Power Electronics Using Halogenated Precursors Silicon Based Mid-Infrared SiGeSn Heterostructure Emitters and Detectors Reconfigurable Electronics and Non-Volatile Memory Research Energy-Filtered Tunnel Transistor: A New Device Concept Toward Extremely Low Energy Consumption Electronics
Energy-Filtered Tunnel Transistor: A New Device Concept Toward Extremely Low Energy Consumption ElectronicsTBMG-2639102/01/2017
Silicon Based Mid-Infrared SiGeSn Heterostructure Emitters and DetectorsTBMG-2638902/01/2017
Energy-Filtered Tunnel Transistor: A New Device Concept Toward Extremely Low Energy Consumption Electronics17AERP02_0902/01/2017
Altering the thermal characteristics of semiconductors can prolong battery life. Office of Naval Research, Arlington, Virginia Excessive heat dissipation (or power consumption) of modem integrated circuits is an undesirable effect that imposes substantial limitations on the performance of many electronic devices. For example, the level of heat dissipation /power consumption of smart phones, tablets, and laptops is such that it prohibits a continuous and prolonged operation of these devices, requiring frequent recharging. Large power consumption of electronic devices requires large energy storage in batteries, increasing the battery weights that soldiers carry in their missions or the weights of remote controlled equipment such as unmanned aerial vehicles (UAVs). Therefore, technology that enables electronic devices to operate with extremely small energy consumption promises a broad range of commercial, military and space applications. The root cause of heat dissipation of current metal
Silicon Based Mid-Infrared SiGeSn Heterostructure Emitters and Detectors17AERP02_0702/01/2017
Enhancing the performance of GeSn p-i-n photodiodes using gold metal nanostructures. Air Force Research Laboratory, Arlington, Virginia The goal of this research project was to advance the science and technology of silicon-based photonic devices using SiGeSn heterostructures. Such devices work in mid-IR spectral range and form the foundation for mid-IR photonics that enable on-chip systems for applications ranging from vibrational spectroscopy, chem/bio sensing, medical/health uses, to environmental monitoring. This project was mostly directed toward improving GeSn detectors with the use of surface plasmons induced by carefully designed metal nanostructures. The goal was to replace the current mid-IR detectors that are usually photodiodes made from narrow bandgap III-V or II-VI semiconductor compounds such as InGaAs, InSb, HgCdTe (MCT) or type-II InGaAs/InGaSb superlattice. These photodiodes are incompatible with the CMOS process and cannot be easily integrated with Si electronics. The
Addendum of Self-Aligned Ion Implant to Design and Processing of SiC High-Temperature Transistors for Durable Operation Above 400 °CTBMG-2550610/01/2016
Researchers at NASA’s Glenn Research Center have developed a revolutionary new generation of silicon carbide (SiC) integrated circuit (IC) chips, setting an unprecedented benchmark in the field of high-temperature electronics. In the past, SiC ICs could not withstand more than a few hours of 500 °C temperatures before degrading or failing. Now, Glenn has successfully fabricated prototype chips that can exceed 10,000 hours of continuous operation at 500 °C. The advanced performance stems in part from the development of Glenn’s patented iridium interfacial stack (IrIS), a bondable metallization stack that prevents diffusion of oxygen and gold into silicon carbide (SiC) integrated circuits operating above 500 °C. The enhanced reliability of these components (and the transistors and logic boards they support) will enable important improvements in the control and operation of combustion engines, well-drilling, and other harsh environment systems, thereby greatly impacting operational
An Investigation into the Tradespace of Advanced Wide-Band Gap Semiconductor Devices in a Full-Bridge DC-DC Converter2016-01-199009/20/2016
In aerospace applications, it is important to have efficient, small, affordable, and reliable power conversion units with high power density to supply a wide range of loads. Use of wide-band gap devices, such as Silicon Carbide (SiC) and Gallium Nitride (GaN) devices, in power electronic converters is expected to reduce the device losses and need for extensive thermal management systems in power converters, as well as facilitate high-frequency operation, thereby reducing the passive component sizes and increasing the power density. A performance comparison of state-of-the art power devices in a 10 kW full-bridge dc-dc buck converter operating in continuous conduction mode (CCM) and at switching frequencies above 100 kHz will be presented in this manuscript. Power devices under consideration are silicon (Si) IGBT with Si antiparallel diodes, Si IGBT with SiC antiparallel diodes, Si MOSFETs, SiC MOSFETs, and enhancement-mode GaN transistors. A 10 kW full-bridge dc-dc converter operating
Kondrath, Nisha, Smith, Nathaniel
Fast, Stretchy Circuits Could Yield New Wearable ElectronicsTBMG-2478306/14/2016
The consumer marketplace is flooded with a lively assortment of smart wearable electronics that do everything from monitor vital signs, fitness or sun exposure to play music, charge other electronics or even purify the air around you — all wirelessly. Now, a team of University of Wisconsin—Madison engineers led by Zhenqiang “Jack” Ma, the Lynn H. Matthias Professor in Engineering and Vilas Distinguished Achievement Professor in electrical and computer engineering, has created the world’s fastest stretchable, wearable integrated circuits, an advance that could drive the Internet of Things and a much more connected, high-speed wireless world.
Current Source Logic GateTBMG-2482906/01/2016
High-temperature electronic integrated circuits have been demonstrated in silicon carbide (SiC) depletion mode MESFETs. This process is only capable of producing depletion mode n-channel MESFET transistors. With only this type of transistor, designing a logic gate is a challenge. A previous logic gate design that can be constructed in the current process has performed well. This invention improves upon the previous design by increasing output voltage range and decreasing the physical layout size of a logic gate. This logic gate circuit consists of depletion mode MESFET/JFET transistors and resistors that can be constructed with SiC depletion mode n-channel MESFETs.
DC Motor with Salient Poles Rotor and All Coils Placed on the Stator2016-01-000104/05/2016
DC motors are the most controllable electrical machines but more complicated for fabrication, in comparison with induction motors having simplified design but more complicated for control. Regular DC motor contain excitation (field) coil on the stator and armature coil on the rotor. Armature coil connected with external voltage source by a mechanical commutator with brushes. This arrangement complicates fabrication of DC machine, increases its cost, lowered reliability, and demands regular maintenance. Electromagnets inside of the stator increase dimensions of DC motor. In DC motor with salient pole rotor, there are no coils on the rotor, and mechanical commutator with brushes is eliminated, and eliminated all disadvantages connected with this arrangement. In this paper, we consider the new version of DC machine with DC stator excitation in compare with presented earlier. The difference is in using individual coil excitation for each armature coil, placed on the stator. In this case
Gladyshev, Sergey P., Gladyshev, Pavel, Okrainskaya, Irina
IGBT Gate Control Methods to Reduce Electrical Power Losses of Hybrid Vehicles2016-01-122404/05/2016
Reducing the loss of the power control unit (PCU) in a hybrid vehicle (HV) is an important part of improving HV fuel efficiency. Furthermore the loss of power devices (insulated gate bipolar transistors (IGBTs) and diodes) used in the PCU must be reduced since this amounts to approximately 20% of the total electrical loss in an HV. One of the issues for reducing loss is the trade-off relationship with reducing voltage surge. To restrict voltage surge, it is necessary to slow down the switching speed of the IGBT. In contrast, the loss reduction requires the high speed switching. One widely known method to improve this trade-off relationship is to increase the gate voltage in two stages. However, accurate and high-speed operation of the IGBT gate control circuit is difficult to accomplish. This research clarifies a better condition of the two-stage control and designed a circuit that improves this trade-off relationship by increasing the speed of feedback control. Combining two-stage
Osanai, Yosuke, Wasekura, Masaki, Yamawaki, Hideo, Shindo, Yusuke
Transmission-Mounted Power Control Unit with High Power Density for Two-Motor Hybrid System2016-01-122304/05/2016
A second-generation power control unit (PCU) for a two-motor hybrid system is proposed. An optimally designed power module, which is a key component of the PCU, is applied to increase heat-resistant temperature, while the basic structure of the first generation is retained and the power semiconductor chip is directly cooled from the single side. In addition to the optimum design, by decreasing the power loss as well as increasing the heat-resistant temperature of the power semiconductors (IGBT: Insulated Gate Bipolar Transistor and FWD: Free Wheeling Diode), the proposed PCU has attained 25% higher power density and 23% smaller size compared to first-generation units, maintaining PCU efficiency (fuel economy). To achieve a high yield rate in the power module assembly process, a new screening technology is adopted at the initial stage of power module manufacturing. In the proposed technology, the maximum current required by hybrid systems can be applied to the component power
Kashimura, Yukiya, Negoro, Yuki
Could Black Phosphorus be the Next Silicon?TBMG-2274808/14/2015
As scientists continue to hunt for a material that will make it possible to pack more transistors on a chip, new research from McGill University and Université de Montréal adds to evidence that black phosphorus could emerge as a strong candidate. In a recent study, researchers reported that when electrons move in a phosphorus transistor, they do so only in two dimensions. This finding suggests that black phosphorus could help engineers surmount one of the big challenges for future electronics – designing energy-efficient transistors.
Improving Organic Transistors that Drive Flexible ElectronicsTBMG-2236006/17/2015
A revolution is coming in flexible electronic technologies as cheaper, more flexible, organic transistors come on the scene to replace expensive, rigid, silicone-based semiconductors. But materials scientists at the University of Massachusetts Amherst say not enough is known about how bending in these new thin-film electronic devices will affect their performance.
Method for Providing Semiconductors Having Self-Aligned Ion ImplantTBMG-2219606/01/2015
This is a modification to technology for realizing durable and stable electrical functionality of high-temperature transistors. This modification is believed crucial to experimental implementation of SiC junction field effect transistors that electrically operated continuously at 500 °C for over 10,000 hours in an air ambient with less than 10% change in operational transistor parameters.
Electronic Warfare TechnologyTBMG-2188104/01/2015
Military electronic warfare (EW) systems including navigation, radar guidance, terrain mapping and others, require lightweight compact components, with radio frequency (RF) output power levels to several kilowatts typically needed to meet system requirements. As GaN transistor technology advances in frequency and power output, solid state power amplifiers (SSPAs) have begun replacing traveling wave tubes (TWTs) at frequencies up to 6 GHz. The utilization of this technology results in a lower cost and greater efficiency over the life of a product.
Radiation Hard By Design (RHBD) ElectronicsTBMG-2105412/01/2014
Current RHBD electronics are limited to speeds that approximate 250 MHz, regardless of the electronic process. The fact that determines the final speed is based on the nature of the current SEU (single-event upsets) radiation-tolerant latches, and the data flow between the latches through combinational logic.
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