A 200-mA, 93% peak power efficiency, single-inductor, dual-output DC–DC buck converter

A single-inductor dual-output (SIDO) DC–DC buck converter is presented. The circuit uses only one (external) inductor to provide two independent output voltages ranging from 1.2 V to the power supply (2.6–5 V) with a maximum total output current of 200 mA. The proposed converter has been fabricated in a 0.35-μm p-substrate CMOS technology. Measurement results demonstrate that a peak power efficiency as high as 93.3% can be achieved. An automatic substrate bias switch technique, that cancels the body effect of the p-channel output power transistors, improves the converter power efficiency performance.     

High efficiency class-Ⅰ audio power amplifier using a single adaptive supply

A high efficiency class-Ⅰ linear audio power amplifier (PA) with an adaptive supply is presented.Its efficiency is improved by a dynamic supply to reduce the power transistors' voltage drop.A gain comp...     

A contactless power transfer system using a series–series–parallel resonant converter

In this article, a contactless power transfer system using a series–series–parallel resonant converter (SSPRC) is proposed. The proposed converter can improve on or eliminate the disadvantages of the contactless system based on conventional resonant converters, since it independently compensates for a primary side leakage inductance, a secondary side leakage inductance and a magnetising inductance. The proposed converter also reduces the circulating currents and the reactive power by controlling the phase angle difference between the inverter output voltage and the current. In addition, the system design can be simplified, since the voltage gain is determined only by the transformer turns ratio for the overall load range without being affected by the other transformer parameters. The proposed converter is analysed with respect to the gain and current margin. The system design procedure is then described for the proposed circuit based on the circuit analysis. Finally, the experimental results are presented in order to verify the proposed contactless power supply.     

A novel PWM control for a bi-directional full-bridge DC–DC converter with smooth conversion mode transitions

A novel CMOS integrated pulse-width modulation (PWM) control circuit allowing smooth transitions between conversion modes in full-bridge based bi-directional DC–DC converters operating at high switching frequencies is presented. The novel PWM control circuit is able to drive full-bridge based DC–DC converters performing step-down (i.e. buck) and step-up (i.e. boost) voltage conversion in both directions, thus allowing charging and discharging of the batteries in mobile systems. It provides smooth transitions between buck, buck-boost and boost modes. Additionally, the novel PWM control loop circuit uses a symmetrical triangular carrier, which overcomes the necessity of using an output phasing circuit previously required in PWM controllers based on sawtooth oscillators. The novel PWM control also enables to build bi-directional DC–DC converters operating at high switching frequencies (i.e. up to 10?MHz and above). Finally, the proposed PWM control circuit also allows the use of an average lossless inductor-current sensor for sensing the average load current even at very high switching frequencies. In this article, the proposed PWM control circuit is modelled and the integrated CMOS schematic is given. The corresponding theory is analysed and presented in detail. The circuit simulations realised in the Cadence Spectre software with a commercially available 0.18?µm mixed-signal CMOS technology from UMC are shown. The PWM control circuit was implemented in a monolithic integrated bi-directional CMOS DC–DC converter ASIC prototype. The fabricated prototype was tested experimentally and has shown performances in accordance with the theory.     

Inorganic perovskite/organic tandem solar cells with efficiency over 20%

The rapid development of perovskite solar cells is beyond our imagination.The power conversion efficiency(PCE)of organic-inorganic hybrid perovskite solar cells has reached 25.5%(https://www.nrel.gov/pv/cell-efficiency.html).However,the unsatisfactory stability of hybrid perovskites is an obstacle for their commercialization,which results from the volatile and hygroscopic organic cations[1].     

A 0.18μm CMOS dual-band low power low noise amplifier for a global navigation satellite system

This paper presents a dual-band low noise amplifier for the receiver of a global navigation satellite system. The differences between single band and multi-band design methods are discussed.The relevant parameter analysis and the details of circuit design are presented.The test chip was implemented in a TSMC 0.18μm 1P4M RF CMOS process.The LNA achieves a gain of 16.8 dB/18.9 dB on 1.27 GHz/1.575 GHz.The measured noise figure is around 1.5-1.7 dB on both bands.The LNA consumes less than 4.3 mA of current ...     

满足更高能量转换效率的要求新型IC帮助克服传统拓扑的局限

能耗是非常热门的话题,能量转换也因此具有更加重要的意义.电子设备已经成为我们日常生活中必不可少的一部分,减少这些设备的能耗将具有非常重要的意义.     

High single-mode power conversion efficiency vertical-cavitytop-surface-emitting lasers

We report advances in the power conversion (wall-plug) efficiency of vertical-cavity top-surface-emitting lasers. The devices were fabricated from molecular beam epitaxial layers using deep proton implants to define gain-guided lasers. The epitaxial structure included low resistance, piecewise linearly graded n-type and p-type mirrors, a triple In_0.2Ga_0.8As quantum-well active region, and a delta-doped contact layer. Power conversion efficiencies as high as 12.7% for continuous-wave single-mode operation were measured after several hours of device operation     

Controlling J‐aggregate formation for increased short‐circuit current and power conversion efficiency with a squaraine donor

A squaraine dye is tested for novel application in a near‐infrared‐active organic photovoltaic cell that is subsequently optimized to obtain a power conversion efficiency of 2.4 ± 0.3%. The optimization utilizes an Alq3 buffer layer and macroscopic structure control through the addition of co‐solvents in the spin‐casting process. Co‐solvent addition increases the amount of aggregates present as measured through linear absorption spectroscopy, and there is a concurrent increase in both efficiency and short‐circuit current. An interpretation of the greatly increased current density is presented that describes how increased J‐aggregation likely increases hole mobility and, as a result, charge separation of the photogenerated excited state. Copyright © 2012 John Wiley & Sons, Ltd.     

光纤喇曼放大器的功率转换效率分析

在定义光纤喇曼放大器(FRA)功率转换效率(PCE)的基础上,考察了不同工作条件下光纤喇曼放大器的功率转换效率,分析PCE与光纤喇曼放大器的输入信号功率、输入泵浦功率和光纤长度的关系,比较了分布式与集总式FRA的功率转换效率,给出提高FRA功率转换效率的途径。     

A new inverter-based charge pump circuit with high conversion ratio and high power efficiency

The current paper presents a new inverter-based charge pump circuit with high conversion ratio and high power efficiency. The proposed charge pump, which consists of a PMOS pass transistor, inverter-based switching transistors, and capacitors, can improve output voltage and conversion ratio of the circuit. The proposed charge pump was fabricated with TSMC 0.35 μm 2P4M CMOS technology. The chip area without pads is only 0.87 mm×0.65 mm. The measured results show that the output voltage of the four-stage charge pump circuit with 1.8 V power supply voltage (V_DD=1.8 V) can be pumped up to 8.2 V. The proposed charge pump circuit achieves efficiency of 60% at 80 μA.     

Very high CW output power and power conversion efficiency from current-confined CDH-LOC diode lasers

CDH-LOC lasers with tight current confinement to the lasing region provide CW output powers as high as 165 mW. The overall power conversion efficiency in CW operation reaches values of 35% (front-facet emitted power/overall input electrical power). Single-longitudinal-mode and fundamental-mode operations are achieved to 40 mW CW and 60 mW peak power (50% duty cycle), respectively. The threshold-current temperature coefficient T0 reaches values of 185 K.     

同向抽运喇曼放大器功率转换效率的数值分析

为了对同向抽运光纤喇曼放大器的功率转换效率进行研究,由耦合方程出发,采用龙格-库塔算法的数值模拟方法,详细分析了所有物理因素对同向抽运光纤喇曼放大器功率转换效率的影响. 结果表明,功率转换效率先随着光纤长度的增加而增加,当增加到最大值时保持数值不变;并且功率转换效率也随着初始信号光功率、光纤喇曼增益系数、信号光损耗系数的增加而增加,但随着光纤有效面积、抽运光损耗系数、抽运光与信号光的频率比的增加而减小;功率转换效率和初始抽运光功率呈抛物线曲线关系. 这对同向抽运光纤喇曼放大器功率转换效率的进一步研究以及光纤喇曼放大器的相关研究有一定参考意义.     

48% power conversion efficiency in single pump gain-shiftedthulium-doped fibre amplifier

A new pumping scheme (1.2 μm+1.4 μm) is demonstrated for a gain-shifted thulium-doped fibre amplifier (TDFA), leading to record efficiency of 48% using one single pump dual-wavelength laser     

Ultra-high-power quasi-CW monolithic laser diode arrays with high power conversion efficiency

An optical power output of 134 W from one facet and power conversion efficiencies as high as 49% have been obtained from monolithic AlGaAs laser arrays with 1 cm emitting widths for 150^s pulse widths (quasi-CW operation). The arrays have etched grooves to prevent transverse lasing and amplified spontaneous emission.     

Three-phase power frequency conversion with high efficiency and high spectral purity

It is shown that a pulse-width modulation circuit may be made to approach ideal product-modulator behaviour at low frequencies. The output of such a modulator contains sum and difference-frequency components: it is shown that the sum-frequency components may be made to cancel each other out completely in a 3-phase system.