Negative impedance converter

About: Negative impedance converter is a research topic. Over the lifetime, 5801 publications have been published within this topic receiving 87636 citations.

Circuit arrangement for operating a high-pressure discharge lamp

Abstract: A circuit for operating a discharge lamp (1) by means of a direct voltage. The circuit comprises direct voltage terminals (A,B) for connection of a direct voltage source, alternating voltage output terminals (K,L) for connection to the discharge lamp, a direct voltage/alternating voltage sine converter (3), and a current limiter (5) for limiting the current through the lamp in its operating condition. A controllable direct voltage converter (2) is coupled between the sine converter and the direct voltage input terminals.

Current Source for Multifrequency Broadband Electrical Bioimpedance Spectroscopy Systems. A Novel Approach

Abstract: New research and clinical applications of broadband electrical bioimpedance spectroscopy arise; increasing the upper limit frequency used in the measurement systems. The current source, an essential block of an electrical bioimpedance impedance analyzer, must have a large-enough output impedance at any frequency of operation to keep the output current constant regardless of the value of working load. In this paper a novel approach to increase the output impedance of a common voltage controlled current source is proposed. The circuit is analyzed, implemented and tested. The results, remarking the significant effect of the circuit parasitic capacitances, show a clear increment of the output impedance, but smaller than the originally expected.

A New Nonisolated High-Voltage-Gain Boost Converter With Inherent Output Voltage Balancing

Abstract: In this paper, a new nonisolated high-voltage-gain boost converter is proposed. The proposed converter is constructed by adding an additional inductor to a conventional three-level-boost (TLB) converter. When compared with the conventional boost and TLB converters, the proposed converter can achieve higher voltage conversion ratio with reduced voltage and current stresses in the switches. In particular, the proposed converter can reduce the losses of active devices by reducing the current of the switch compared to conventional converters, thus, can achieve high efficiency. In addition, the proposed converter automatically balances the output voltages for an unbalanced load without the need for any additional control strategy or auxiliary circuit. A 2-kW prototype converter was built and tested to verify performances of the proposed converter.

Device design guideline for steep slope ferroelectric FET using negative capacitance in sub-0.2V operation: Operation speed, material requirement and energy efficiency

Abstract: We have shown a practical device design guideline for sub-0.2V ultra-low power, steep slope ferroelectric FET using negative capacitance (NC) focusing on operation speed, material requirement, and energy efficiency for the first time. The operation speed is determined by finite switching time of ferroelectric polarization. For low supply voltage and hysteresis-free design, there exists a ferroelectric material parameter window to maximize the benefit of steep slope by NC. By the optimized device design, the energy efficiency is improved by 2.5x. The minimum energy voltage is pushed down to sub-0.2V range.

A New PWM-Controlled Quasi-Resonant Converter for a High Efficiency PDP Sustaining Power Module

Abstract: A new pulsewidth modulation (PWM)-controlled quasi-resonant converter for a high-efficiency plasma display panel (PDP) sustaining power module is proposed in this paper. The load regulation of the proposed converter can be achieved by controlling the ripple of the resonant voltage across the primary resonant capacitor with a bidirectional auxiliary circuit, while the main switches are operating at a fixed duty ratio and fixed switching frequency. Hence, the waveforms of the currents can be expected to be optimized from the view-point of conduction loss. Furthermore, the proposed converter has good zero-voltage switching (ZVS) capability, simple control circuits, no high-voltage ringing problem of rectifier diodes, no dc offset of the magnetizing current and low-voltage stresses of power switches. Thus, the proposed converter shows higher efficiency than that of a half-bridge LLC resonant converter under light load condition. Although it shows the lower efficiency at heavy load, because of the increased power loss in auxiliary circuit, it still shows the high efficiency around 94%. In this paper, operational principles, features of the proposed converter, and analysis and design considerations are presented. Experimental results demonstrate that the output voltage can be controlled well by the auxiliary circuit using the PWM method.