A magnetically isolated gate driver for high-speed voltage sharing in series-connected MOSFETs

A scalable resonant gate drive circuit is described, suitable for driving series-connected MOSFETs in high-voltage, high-speed inverter applications for resistive and capacitive loads. Galvanic isolation is provided by a loop of high voltage wire, which also serves as the resonant inductor in the circuit. Fast dynamic voltage sharing is achieved by delivering equal current to each gate. A prototype is built and tested, demonstrating a 75ns switching time at 5kV using 900V MOSFETs

Magnetic pulse generation for high-speed magneto-optic switching

In this article, the magnetic pulse characteristics needed to achieve high-speed magneto-optic (MO) switching are investigated. A fiber-based, MO, low-voltage optical switch capable of 200 ns switching is presented, along with the special circuit characteristics for magnetic field generation for high-speed switching. The switch consists of the optical system, the MO material (bismuth substituted iron garnet [(Bi1.1Tb1.9)(Fe4.25Ga0.75)O12]), and a high-speed magnetic field driving circuit. A Faraday rotator is placed within the interferometric loop of a fiber-optic Sagnac interferometer, and interference at the output ports is controlled by the applied field. The fast switching speed is accomplished via the special design of the magnetic pulse generation circuitry. The applied magnetic field overshoots the field necessary to achieve the desired Faraday rotation and then settles to a steady state field. If the duration of the overshoot is less than the time it takes the material to saturate, a fast optical switching time can be achieved without saturating the material. The effects of the overshoot amplitude and duration and steady-state amplitude on optical rise time (determined by domain wall velocity) are studied and experimental results are presented

Diode reverse recovey time

The reverse recovery time of a diode will be defined in terms of the time required for a specified reverse current transient in the diode circuit to decay to particular value. This transient is important to the designers of fast switching circuits, such as those used in high speed computers, because it represents an upper limit to the switching speed of the diode

Analysis of Voltage Regulator Module (VRM) Noise Coupling to High-Speed Signals with VRM Via Designs

The Physical Noise Coupling Mechanism between Voltage Regulator Module (VRM) Noise Coupling to High-Speed Signal Traces is Analyzed and Different Noise Reduction Methods Are Analyzed for the First Time. the Rapid Switching of Field Effect Transistors (FETs) Creates an Unintentional Coupling Region Around the VRM. as High-Speed Traces Are Often Routed in the Inner Signal Layers of Printed Circuit Boards (PCBs) as Striplines for Signal Integrity, the VRM Switching Noise is Mainly Coupled from Noisy Power Vias to the Victim Traces Routed Around the VRM Region. to Analyze Different Coupling Reduction Methods in Practical High-Speed Channels, a Simplified PCB Design based on a High-Speed Server Platform is Proposed. Case Studies under Various Conditions Verifies the Most Effective VRM Noise Coupling Reduction Method. Different Design Parameters that Influence the VRM Noise Coupling Are Analyzed to Provide a Design Guide for High-Speed Channel Designers

High-Voltage Ignition Circuit For Compressed Natural Gas Direct Injection Engine

Ignition system of an internal combustion engine is an important part of the overall engine management system. It is a means to provide enough high-voltage, minimum around 20 kV to form an arc across the gap of a spark plug and to control the ignition timing. Thus, it can provide a right time to burn the air-fuel mixture inside the engine. With advances in technology, the ignition system has progressed from a contact point ignition system to an electronic ignition system and then to a digital distributorless ignition system. The increased growth of the ignition system design in both size and complexity has brought about the need for a simple and reliable ignition system to provide high-voltage output to be delivered to the spark plug and at the same time to adapt with the natural gas engine environment. Therefore, with the development of an economical and reliable ignition system, there is a growing interest in developing digital distributorless ignition system, which is programmable making it more flexible and superior to other conventional system. This thesis presents the development of an ignition circuit for a coil-on plug ignition system of a natural gas engine. The main specification of the circuit is the implementation of the ignition power-switching device at the primary side of the circuit to provide high switching speed to turn on and off the device. The chosen power-switching device was Insulated Gate Bipolar Transistor or IGBT, which is more suitable to be implemented inside the circuit design compared to other power-switching devices. The selected IGBT, IRGB14C40L are specifically design for a ignition applications and small engine ignition circuit. It has low saturation voltage and high self-clamped inductive switching energy. The modelling and optimization of the ignition IGBT parameters is done in the PSPICE software to fulfill the real ignition power-switching device requirements. The other specification of the circuit design is the implementation of the snubber circuit, which can provide over-voltage protection at the primary side of the power-switching device. Finally, the testing of the circuit is done by applying a control signal at the input source terminal or at the gate terminal of the ignition IGBT. The complete circuit design is integrated with the high-voltage ignition coil and a special designed long neck spark plug for the natural gas engine purpose. The circuit has been tested to make sure it can provide the desired voltage so it can ignite the mixture of the air and compressed natural gas in the right cylinder and at the right time. From the test results of the ignition circuit, it demonstrates that the performances of the ignition parameters such as the primary current and secondary voltage are highly affected by the device parameters like the ignition IGBT parameters, specifications of the high-voltage ignition coil as well as the control strategy of the switching-time to ignite the spark plug

Noise-dissipation relation for nonlinear electronic circuits

An extension of fluctuation-dissipation theorem is used to derive a "speed limit" theorem for nonlinear electronic devices. This speed limit provides a lower bound on the dissipation that is incurred when transferring a given amount of electric charge in a certain amount of time with a certain noise level (average variance of the current). This bound, which implies a high energy dissipation for fast, low-noise operations (such as switching a bit in a digital memory), brings together recent results of stochastic thermodynamics into a form that is usable for practical nonlinear electronic circuits, as we illustrate on a switching circuit made of an nMOS pass gate in a state-of-the-art industrial technology

Ultra High Speed Short Circuit Protection for IGBT with Gate Charge Sensing

Short circuit (SC) protection for IGBT has been crucial issue since IGBTs have become major switching devices for power electronics applications. According to the IGBT performance improvement, chip current density has been increased and the chip has become as thin as 100μm. The high current density and thin wafer chip result in high temperature rising speed during SC condition and hence high speed protection scheme for IGBT is highly required. Conventional methods, such as sense IGBT configuration, have the response time of 5 micro second, for example, which is not sufficient to protect advanced IGBTs. In this paper, we propose a novel protection method with response time shorter than 1 micro second.The 22nd International Symposium on Power Semiconductor Devices & Ics (ISPSD2010), 6月6日-10日, 2010年, International Conference Center Hiroshima, Hiroshima, Japa

Improving circuit miniaturization and its efficiency using Rough Set Theory

High-speed, accuracy, meticulousness and quick response are notion of the vital necessities for modern digital world. An efficient electronic circuit unswervingly affects the maneuver of the whole system. Different tools are required to unravel different types of engineering tribulations. Improving the efficiency, accuracy and low power consumption in an electronic circuit is always been a bottle neck problem. So the need of circuit miniaturization is always there. It saves a lot of time and power that is wasted in switching of gates, the wiring-crises is reduced, cross-sectional area of chip is reduced, the number of transistors that can implemented in chip is multiplied many folds. Therefore to trounce with this problem we have proposed an Artificial intelligence (AI) based approach that make use of Rough Set Theory for its implementation. Theory of rough set has been proposed by Z Pawlak in the year 1982. Rough set theory is a new mathematical tool which deals with uncertainty and vagueness. Decisions can be generated using rough set theory by reducing the unwanted and superfluous data. We have condensed the number of gates without upsetting the productivity of the given circuit. This paper proposes an approach with the help of rough set theory which basically lessens the number of gates in the circuit, based on decision rules.Comment: The International Conference on Machine Intelligence Research and Advancement,ICMIRA-201

An Overview of the Isochronets Architecture for High Speed Networks

This paper overviews a novel switching architecture for high-speed networks: Isochronets. Isochronets time-divide network bandwidth among routing trees. Traffic moves down a routing tree to the root during its time band. Network functions such as routing and flow control are entirely governed by band timers and require no processing of frame headers bits. Frame motions need not be delayed for switch processing, allowing Isochronets to scale over a large spectrum of transmission speeds and support all-optical implementations. The network functions as a media-access layer that can support multiple framing protocols simultaneously, handled by higher layers at the periphery. Internetworking is reduced to a simple media-layer bridging. Isochronets provide flexible quality of service control and multicasting through allocation of bands to routing trees. They can be tuned to span a spectrum of performance behaviors outperforming both circuit or packet switching