电力有源补偿及滞环电流跟踪控制研究

本文在对电力系统有源无功与谐波补偿的原理进行理论分析的基础上,运用其有关分析结果主要讨论一种电力有源滤波器主电路及变结构非线性控制系统的组成和工作原理,给出了一种变结构滞环电流跟踪控制的思路,通过Pspice软件对单相和三相系统进行了仿真研究,仿真结果证实了该系统及控制方法的正确性与可行性。     

Electronically tunable MOSFET-only current-mode biquad filter

A novel current mode MOSFET-only structure with multi-input single-output (MISO) is proposed. The proposed circuit is free from passive circuit elements like resistors and capacitors and able to realize low-pass (LP), band-pass (BP), high-pass (HP), band-stop (BS) and all-pass (AP) filter functions with using the same circuit configuration. It is also important to note that the proposed filter has electronic tunability property. The proposed circuit is laid-out in the Cadence environment using 0.18 µm TSMC CMOS technology parameters. The layout area is only 408 μm² and the power consumption is about 0.6 mW. Furthermore, to investigate the performance of the BP filter output of the proposed MISO filter, Monte Carlo and corner analyses are also presented. It is shown that the mismatches and the process variations cause only small deviations for the BP filter configuration. Furthermore, the noise performance of the proposed filter is also investigated.     

Differential bidirectional transceiver for on-chip long wires

This work presents a differential bidirectional transceiver (DBT) for on-chip long wires. To enhance operating speed and reduce power consumption, the voltage swing on the wire is reduced using current-mode scheme. Consequently, our design performs higher data rate when wire length is extended. Moreover, adoption of differential scheme with a moderate tradeoff of area effectively lowers power supply noise and common mode noise. The receiver adopts four input differential pairs along with current summation circuit to evaluate small signal differences of every that state resulted from transmitting different data. Simulations using 0.18-μm device model indicates that the total input to output delay over a 5 mm long wire is 0.96 ns, with a power consumption of 8.724 mW at a speed of 1.2 Gbps and a maximum achievable data rate of 1.5 Gbps. A test chip is realized and successfully verifies the performance of the transceiver.     

Highly linear micropower class AB current mirrors using Quasi-Floating Gate transistors

A design approach to achieve low-voltage micropower class AB CMOS cascode current mirrors is presented. Both class AB operation and dynamic cascode biasing are based on the use of Quasi-Floating Gate transistors. They allow high linearity for large signal currents and accurately set quiescent currents without requiring extra power consumption or supply voltage requirements. Measurement results show that dynamic cascode biasing allows a wider input range and a linearity improvement of more than 23 dB with respect to the use of conventional biasing. A THD value better than −35 dB is measured for input amplitudes up to 100 times the bias currents. Two class AB current mirror topologies are proposed, with slightly different ways to achieve class AB operation and dynamic biasing. The proposed current mirrors, fabricated in a 0.5 µm CMOS technology, are able to operate with a supply voltage of 1.2 V and a quiescent power consumption of only 36 µW, using a silicon area <0.025 mm².     

Design of 3.1–10.6 GHz ultra-wideband CMOS low noise amplifier with current reuse technique

A new low complexity ultra-wideband 3.1–10.6 GHz low noise amplifier (LNA), designed in a chartered 0.18 μm RFCMOS technology, is presented in this paper. The ultra-wideband LNA only consists of two simple amplifiers with an inter-stage inductor connected. The first stage utilizing a resistive current reuse and dual inductive degeneration techniques is used to attain a wideband input matching and low noise figure. A common source amplifier with inductive peaking technique as the second stage achieves high flat gain and wide the −3 dB bandwidth of the overall amplifier simultaneously. The implemented ultra-wideband LNA presents a maximum power gain of 15.6 dB, a high reverse isolation of −45 dB and a good input/output return losses are better than −10 dB in the frequency range of 3.1–10.6 GHz. An excellent noise figure (NF) of 2.8–4.7 dB was obtained in the required band with a power dissipation of 14.1 mW under a supply voltage of 1.5 V. An input-referred third-order intercept point (IIP3) is −7.1 dBm at 6 GHz. The chip area including testing pads is only 0.8 mm × 0.9 mm.     

35 W集成控制型HID镇流器的设计

设计了一种基于集成芯片控制的HID灯镇流器。该镇流器集成了对恒功率、电流采样、温度补偿、斜坡补偿部分的控制,同时改进了采样电路,有效提高了调制信号的占空比。镇流器电路拓扑结构简单,降低了成本,效率达到80.3%,可靠性高,无声谐振现象。     

电视机谐波电流解决案例剖析

介绍了电视机应符合的谐波电流标准要求,通过对本公司解决电视机谐波电流问题的实际过程进行深入的研究,分析了增加谐波电流标准要求后对电视机开发和生产造成的困难,介绍了我们克服这些困难的经验.     

走近"2001宽带年"

中国互联网发展的带宽不足、上网速度慢,是长期制约我国电信网络发展的瓶颈.随着"2001宽带年"宽带网建设的启动,将为我们早日铺就信息高速公路.     

Photonic theory of noise

The paper proposes that 1/f noise in materials and devices under non-equilibrium conditions is of electromagnetic origin rather than being related to charge carriers. For samples represented by simple resistors the analysis shows that the noise is due to the discrete nature of photons constituting the impinging electromagnetic flux from the source feeding the resistor. The paper presents detailed analysis of the external and internal electromagnetic fields of the resistor environment, with appropriate interpretation in terms of discrete photons. From quantum theory photons are known to retain their energy under interactions in linear environments. This property implies a departure from macroscopic electromagnetics in that photons cannot be partially transmitted and partially reflected, a phenomenon requiring appropriate modifications of boundary conditions at the resistor surface. These special demands call for inclusion of a supplementary internal resistor mode, serving as a lossless idler which is active only for matching purposes. At the resistor terminals the impinging photons give rise to excitation of RF current and voltage noise with an exact 1/f frequency distribution, which is in agreement with all available experimental measurements. The paper presents detailed formulae for noise spectral densities under general drive conditions from DC and RF sources of arbitrary internal resistance. The presented theoretical noise formulae have the same form as earlier empirical formulae for 1/f noise. With an RF source at frequency f₀ the analysis predicts noise with 1/|f-f₀| frequency distribution, which is compatible with available experimental observations.     

一种新型LED恒流驱动电路SC1674S

本文介绍了一种新型的发光二极管（LED）恒流驱动电路SC16749,该电路应用了“智能均衡脉宽调制（B-PWM）”的专利技术,可同时提高LED显示系统的亮度利用率和刷新率这两项重要性能指标,有效解决传统LED显示系统中亮度利用率和刷新率之间的矛盾,提升整个LED显示系统的显示质量。