The Experts below are selected from a list of 38454 Experts worldwide ranked by ideXlab platform

Malgorzata Mareksadowska - One of the best experts on this subject based on the ideXlab platform.

  • on chip Power Supply Network optimization using multigrid based technique
    2003
    Co-Authors: Kai Wang, Malgorzata Mareksadowska
    Abstract:

    In this paper, we present a novel multigrid-based technique for on-chip Power Supply Network optimization. We reduce a large-scale Network to a much coarser one which can be efficiently optimized. The solution for the original Network is then quickly computed using a back-mapping process. We model the Power grid by an RLC Network and use time-varying current sources to capture the on-chip switching. Our technique is capable of optimizing Power grid and decoupling capacitance simultaneously. Experimental results show that the proposed technique provides more robust and area-efficient solutions than those obtained by the earlier approaches. It also provides a significant speed-up and brings up a possibility of incorporating Power Supply Network optimization into other physical design stages such as signal routing.

Kai Wang - One of the best experts on this subject based on the ideXlab platform.

  • On-chip Power-Supply Network optimization using multigrid-based technique
    2005
    Co-Authors: Kai Wang, M. Marek-sadowska
    Abstract:

    In this paper, we present a novel multigrid-based technique for the problem of on-chip Power-Supply Network optimization. The multigrid-based technique is applied to reduce a large-scale Network to a much coarser one. The reduced Network can be efficiently optimized. The solution for the original Network is then quickly computed using a back-mapping process. Due to the adoption of an accurate resistance-inductance-capacitance Power-Supply Network and time-varying switching-current model, our technique is capable of optimizing Power grid and decoupling capacitance simultaneously. Experimental results show that large-scale Power-Supply Networks with millions of nodes can be solved in a few minutes. The proposed technique not only speeds up significantly the optimization process, without compromising the quality of solutions, but also brings up a possibility of incorporating the Power-Supply Network optimization into other physical design stages such as signal routing.

  • on chip Power Supply Network optimization using multigrid based technique
    2003
    Co-Authors: Kai Wang, Malgorzata Mareksadowska
    Abstract:

    In this paper, we present a novel multigrid-based technique for on-chip Power Supply Network optimization. We reduce a large-scale Network to a much coarser one which can be efficiently optimized. The solution for the original Network is then quickly computed using a back-mapping process. We model the Power grid by an RLC Network and use time-varying current sources to capture the on-chip switching. Our technique is capable of optimizing Power grid and decoupling capacitance simultaneously. Experimental results show that the proposed technique provides more robust and area-efficient solutions than those obtained by the earlier approaches. It also provides a significant speed-up and brings up a possibility of incorporating Power Supply Network optimization into other physical design stages such as signal routing.

Kaushik Roy - One of the best experts on this subject based on the ideXlab platform.

  • minimizing ohmic loss and Supply voltage variation using a novel distributed Power Supply Network
    2006
    Co-Authors: Mark M Budnik, Kaushik Roy
    Abstract:

    IR and di/dt events may cause ohmic losses and large Supply voltage variations due to system parasitics. Today, parallelism in the Power delivery path is used to reduce ohmic loss while decoupling capacitance is used to minimize the Supply voltage variation. Future integrated circuits, however, will exhibit large enough currents and current transients to mandate additional safeguards. A novel, distributed Power delivery and decoupling Network is introduced reducing the Supply voltage variation magnitude by 67% and the future ohmic loss by 15.9W (compared to today’s Power delivery and decoupling Networks) using conventional processing and packaging techniques in a 130nm technology node.

  • a novel wavelet transform based transient current analysis for fault detection and localization
    2005
    Co-Authors: Swarup Bhunia, Kaushik Roy
    Abstract:

    Transient current (IDD) testing has been often cited and investigated as an alternative and/or supplement to quiescent current (IDDQ) testing. In this correspondence, we present a novel integrated method for fault detection and localization using wavelet transform-based IDD waveform analysis. The time-frequency resolution property of wavelet transform helps us detect as well as localize faults in digital CMOS circuits. Experiments performed on measured data from a fabricated 8-bit shift register, and simulation data from more complex circuits show promising results for both detection and localization. Wavelet-based detection method shows better sensitivity than spectral and time-domain methods. Effectiveness of the localization method in presence of complex Power Supply Network, measurement noise, and process variation is also addressed.

  • frequency domain analysis of switching noise on Power Supply Network
    2000
    Co-Authors: S Zhao, Kaushik Roy, Chengkok Koh
    Abstract:

    In this paper, we propose an approach for the analysis of Power Supply noise in the frequency domain for Power/ground (P/G) Networks of tree topologies. We model the P/G Network as a linear time invariant (LTI) pseudo-distributed RLC Network and the gates (or cells) as time-varying current sources. Voltage fluctuation caused by the switching events is calculated based on the effective impedances seen by the corresponding current sources and the spatial correlation between the nodes of the Power Network. Superposition is applied to the LTI system to obtain the overall noise spectrum at any node of the Power Supply Network. Inverse Fast Fourier Transformation (IFFT) is then performed on the frequency domain noise spectrum to obtain the time domain noise waveform. The proposed algorithm has a complexity of O(n/sup 2/). Experimental results show that our approach can produce accurate noise waveforms.

  • estimation of inductive and resistive switching noise on Power Supply Network in deep sub micron cmos circuits
    2000
    Co-Authors: S Zhao, Kaushik Roy, Chengkok Koh
    Abstract:

    In this paper, we propose an event-driven simulation based approach to estimate the worst case IR drop and Ldi/dt inductive noise an the Power Supply Network. The switching noise is modeled as a weighted sum of the switching currents and the rates of change of the switching currents, where the weights are respectively the effective resistance and inductance (on the P/G Network) experienced by each switching current. Monte Carlo and genetic algorithm are employed to search for the worst case input vector pair(s) that induce the maximum switching noise. The worst case input patterns are used in the SPICE simulation to verify the switching noise waveforms on the Power Supply Network. Experimental results show that the worst case switching noise on the Power Supply Network for ISCAS85 benchmark circuits implemented in TSMC 0.25 /spl mu/m technology can be as high as 40% of the Supply voltage V/sub dd/.

Toshiro Hirose - One of the best experts on this subject based on the ideXlab platform.

  • A Power Efficiency Improvement Technique for a Bidirectional Dual Active Bridge DC–DC Converter at Light Load
    2014
    Co-Authors: Toshiro Hirose, Mika Takasaki, Yoichi Ishizuka
    Abstract:

    Bidirectional dc-dc converters, which make possible the bidirectional transmission of Power, have become indispensable in recent years due to the diversification of the Power Supply Network, including the use of batteries. Of these, the dual active bridge (DAB) dc-dc converter features a simple mechanism and symmetric circuit architecture, making possible the equal transmission of Power in both directions. Because of these advantageous characteristics, DAB dc-dc converters are in wide use. However, this circuit has the intrinsic problems that, during light-load conditions, switching surges occur and Power efficiency decreases. This paper proposes digitally controlled operation as a new method to resolve these problems and reports on an experiment that was carried out using a 1-kW system. In addition, for both buck and boost modes, output Power characteristic equations were derived through application of the extended state-space averaging method, and a loss-included circuit analysis was carried out for the circuit used in the experiment. It was thereby demonstrated that circuit loss was smaller for the proposed operation than that for conventional operation. In the loss-included circuit analysis, for both proposed and conventional operations, equivalent circuits that approximated circuit loss as a single resistance were used. As a result, it was confirmed that, with the operation proposed in this paper, without the use of a snubber circuit, switching surges could be reduced significantly and also that, during light load, there was a Power efficiency improvement of up to 16%. In addition, a loss-included circuit analysis with a single equivalent resistance has been done. The resistance value is assigned with the averaged circuit total resistance. By the analysis, a relation between phase difference and output Power is obtained. The results were confirmed with the experiment.

  • a Power efficiency improvement technique for a bi directional dual active bridge dc dc converter at light load
    2013
    Co-Authors: Mika Takasaki, Yoichi Ishizuka, Tamotsu Ninomiya, Yutaka Furukawa, Toshiro Hirose
    Abstract:

    Recently, the bi-directional dc-dc converter has been focused on because of the huge demand for diversification of Power Supply Network including battery. The dual active bridge (DAB) dc-dc converter is one of the most popular circuits for bi-directional applications because of its simple structure. However, Power efficiency at light load is the intrinsic problem of a bi-directional DAB DC-DC converter. In this paper, the simple solution with digital operation for the problem is proposed and experiments are performed with 1kW system. This method can reduce a switching surge without other circuits such as snubber and improve Power efficiency at light load. Therefore it can reduce loss of switching surge and, improve Power efficiency. From the results, 37% maximum Power efficiency improvement at light load is confirmed. Furthermore, this method is capable of control in the conventional method in the heavy load range. Consequently, it is possible to reduce the switching surge and realize high Power efficiency in a wide load range.

Klaus Dostert - One of the best experts on this subject based on the ideXlab platform.

  • physical and regulatory constraints for communication over the Power Supply grid
    2003
    Co-Authors: M Gebhardt, F Weinmann, Klaus Dostert
    Abstract:

    This article describes the topology of the Power Supply Network in respect to the deployment of Power line communications in different countries. The characteristics of the Power line channel are investigated, and the causes of electromagnetic interference from PLC technology in wireless communications services are discussed. Since the radiation originating from PLC cannot be avoided completely by technical means, a solution via standardization is necessary. The current status of worldwide regulation concerning EMC is presented.

  • physical and regulatory constraints for communication over the Power Supply grid
    2003
    Co-Authors: M Gebhardt, F Weinmann, Klaus Dostert
    Abstract:

    This article describes the topology of the Power Supply Network in respect to the deployment of Power line communications in different countries. The characteristics of the Power line channel are investigated, and the causes of electromagnetic interference from PLC technology in wireless communications services are discussed. Since the radiation originating from PLC cannot be avoided completely by technical means, a solution via standardization is necessary. The current status of worldwide regulation concerning EMC is presented.