A novel decoupling technique for CMOS gate with strong-coupled components is presented. The feedback structure is reduced to a unidirectional one, which facilitates the fast-timing simulation. Based on the waveform re...
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A novel decoupling technique for CMOS gate with strong-coupled components is presented. The feedback structure is reduced to a unidirectional one, which facilitates the fast-timing simulation. Based on the waveform relaxation technique, the decoupling principles and procedures are discussed in detail. Most of the factors, which influence the operation of the strong-coupled components, are taken into account. The proposed method is validated by SPICE simulation.
Current doubler rectifier (CDR) is one of the best candidates for high output current DC-DC converters. In this paper, several conventional CDR snubber circuits are evaluated, and two passive lossless snubber circuits...
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Current doubler rectifier (CDR) is one of the best candidates for high output current DC-DC converters. In this paper, several conventional CDR snubber circuits are evaluated, and two passive lossless snubber circuits for the CDR are proposed to reduce the reverse-recovery-related losses and clamp the voltage spikes across the rectifiers. The snubber circuits are tested and verified experimentally, and higher efficiency is achieved when compared to the conventional resistive snubbers.
This paper, for the first time, studies the influence nMOSFET gate oxide breakdown (BD) has on the performance of CMOS low noise amplifiers (LNA) and power amplifiers (PA) using an equivalent RF circuit model. Cascode...
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This paper, for the first time, studies the influence nMOSFET gate oxide breakdown (BD) has on the performance of CMOS low noise amplifiers (LNA) and power amplifiers (PA) using an equivalent RF circuit model. Cascode LNAs are found to be more reliable than common source LNAs in terms of gate oxide reliability. It is shown for a Class-E PA oxide breakdown effects lead to an increase in the switching transistor's "on" voltage, which, in turn leads to substantial decreases in the output power and drain efficiency.
Power-awareness indicates the scalability of the system energy with changing conditions and quality requirements. Multipliers are essential elements used in DSP applications and computer architectures. Although Boolea...
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Power-awareness indicates the scalability of the system energy with changing conditions and quality requirements. Multipliers are essential elements used in DSP applications and computer architectures. Although Boolean multipliers have natural power awareness to the changing of input precision, deeply pipelined designs do not have this benefit. A 2-dimensional pipeline gating sch.me is proposed in this paper to solve this problem and improve the power awareness in these designs. 2-Dimensional pipeline gating is to gate the clock to registers in both vertical direction (data flow direction in pipeline) and horizontal direction (within each pipeline stage). This technique only needs very little additional area and the overhead is hardly noticeable. A set of array multipliers were designed and tested. Results show that the new 16-bit array multiplier using this technique has an average power saving of 66% and an average latency reduction of 47% over original design under equal input precision probabilities.
Asymmetric control sch.me is an approach to achieve ZVS for half-bridge isolated DC-DC converter. However, it is not suited for wide-range input voltage due to the uneven voltage and current components stresses. This ...
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Asymmetric control sch.me is an approach to achieve ZVS for half-bridge isolated DC-DC converter. However, it is not suited for wide-range input voltage due to the uneven voltage and current components stresses. This paper presents a new "duty-cycle-shifted PWM control" sch.me for half-bridge isolated dc-dc converters to achieve ZVS operation without asymmetric penalties and without adding additional components. Because the duty cycle width is kept identical for both switches, the asymmetric current and voltage stresses problem is eliminated. The principles of operation and key features are illustrated. Experimental results verify that higher efficiency is achieved with the proposed "duty-cycle-shifted" control method, especially at higher switching frequency.
We propose a novel high-index-contrast waveguide structure capable of light strong confinement and guiding in low-refractive-index materials. The principle of operation of this structure relies on the elec.ric field (...
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We propose a novel high-index-contrast waveguide structure capable of light strong confinement and guiding in low-refractive-index materials. The principle of operation of this structure relies on the elec.ric field (E-field) discontinuity at the interface between high-index-contrast materials. We show that by using such a structure the E-field can be strongly confined in a 50-nm-wide low-index region with normalized average intensity of 20 μm -2. This intensity is approximately 20 times higher than that can be achieved in SiO2 with conventional rectangular or photonic crystal waveguides.
Delta-Sigma modulators have been successfully applied to over-sampling digital-to-analog and analog-to-digital data converters. In addition, investigations have been pursued in power elec.ronics applications such as s...
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Delta-Sigma modulators have been successfully applied to over-sampling digital-to-analog and analog-to-digital data converters. In addition, investigations have been pursued in power elec.ronics applications such as switch-mode power supplies and switch-mode inverters. In this paper, delta-sigma modulation is investigated and applied to three-level Neutral Point Clamped Voltage Source Inverters. The high switching frequency power spectra density, common mode voltage reduction and low average switching frequency are discussed. The simulation results show that delta-sigma modulation can effectively reduce the magnitude of the switching frequency power density, increase the efficiency of the inverter and lower the common mode voltage. Experimental results substantiate the simulation results.
This paper presents a new half-bridge isolated dc-dc converter topology associated with a new PWM control method to achieve zero-voltage-switching (ZVS) of all switches. Switching losses and losses related to transfor...
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This paper presents a new half-bridge isolated dc-dc converter topology associated with a new PWM control method to achieve zero-voltage-switching (ZVS) of all switches. Switching losses and losses related to transformer leakage inductance are significantly reduced, which provides converter with the potential to operate at higher efficiency and higher frequency. The principle of operation and features of proposed topology are illustrated and experimentally verified.
Fault-tolerant approaches to digital system design are becoming increasingly important, in particular for mission critical systems. In this paper, a VLSI implementation of a fault-tolerant cell for a reconfigurable DS...
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ISBN:
(纸本)1932415106
Fault-tolerant approaches to digital system design are becoming increasingly important, in particular for mission critical systems. In this paper, a VLSI implementation of a fault-tolerant cell for a reconfigurable DSP processor is described. This cell is based on a 32-bit memory which it is used as a look-up table inside the processor. A cross-parity sch.me is used to provide the error correction capabilities for this cell. This sch.me computes and stores parity bits during write operation, and uses these bits during memory read to identify errors in the system. One error can be corrected during every read operation of the cell. A prototype for this system has been fabricated in 0.5 μm CMOS VLSI technology. Even with this modest technology this circuit exhibits high performance due to its optimized datapath. The maximum delay for this cell is 4.13 nsec.
In previous work, an extension to geometrical optics (EGO) that allows the application to reflecting surfaces that have radii of curvature less than the elec.romagnetic was used to model the microwave backscattering f...
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In previous work, an extension to geometrical optics (EGO) that allows the application to reflecting surfaces that have radii of curvature less than the elec.romagnetic was used to model the microwave backscattering from numerically simulated breaking water wave crests. The same approach has now been applied to plunging wave crest profiles that were directly measured in a wave tank, and the modeled backscattering compared to reference scattering found using moment-method based numerical techniques. When considering the directly measured two-dimensional cross-sections of the breaker, EGO successfully predicts the reduction in the vertically polarized backscatter (VV) observed in the reference scattering through the interference of reflections from the breaker jet itself and the cavity under the jet. A similar reduction is not seen at horizontal polarization (HH), giving a large HH-to-VV ratio at certain times in the breaking process. A three-dimensional scattering profile was synthesized from the 2-D measurements. The EGO-modeled interference of reflections from several different points on the 3-D wave yields a deep null in the VV backscattering that matches the null observed in the reference scattering. Again no interference null is observed in the HH scattering.
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