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本文介绍的是一款制作非常容易,调整方便、性能好、价格低的10W 功率放大器。在本年度日本自制放大器竞赛中荣获大阪赛区第八名。一、电路特点该放大器的电路如图1所示。该电路是由单端推挽(SEPP)电路演变而来的。在电路中对输出晶体三极管的激励方式作了改进,用两个运算放大器分别驱动两只担任互补推挽输出的功率放大管,两只功率放大管通过发射极电阻相连,扬声器接在发射极电路中。该放大器电路与以往的 SEPP 电路(图2)在下面四个方面有所不同。(1)不需要偏置电路。(2)用运算放大器的输出直接驱动功率放大管。(3)偏置电压的稳定度极高。(4)不需要静噪电路。下面就这四个不同点加以说明。在该电路中由于使用了两个运算放大器,运算放大器本身兼作输出电平的 相似文献
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硅基有机发光微显示像素驱动电路设计 总被引:1,自引:1,他引:0
由于微型显示像素面积的限制,硅基有机发光微显示像素驱动电路需要实现足够小的驱动电流.文章提出的三管电压控制型像素驱动电路与常规的采用电流镜电路的电流控制型像素驱动电路都能实现微显示所需的小电流驱动.利用Synopsys公司的H-spice软件对两种电路仿真比较,发现电流控制型电路具有线性灰度和较宽的有效灰度范围,但是通过调整电压控制型电路中与OLED并联的晶体管的宽长比,即可使其有效灰度范围与电流控制型电路可比.同时也发现电流控制型电路的功耗是电压控制型电路的4倍以上,且电路形式较复杂,工艺要求较高.所以三管电压控制型电路更适合于硅基有机发光微显示驱动电路. 相似文献
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SEPP为Single-Ended Push-Pull的字头,原意为单端推挽电路。SRPP为Shunt Regulated Push—Pull的字头,原意为分压调整式推挽电路。这两种推挽电路均属推挽两管并联驱动负载的单端推挽电路,其区别是,SEPP需由倒相器提供两路相位相反的驱动信号,而SRPP只需一组驱动信号,通过串联于两管之间的分压电阻为另一推挽管提供相位相反的驱动信 相似文献
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<正> 目前国内生产的荧光灯电子镇流器绝大多数采用驱动变压器式的半桥拓扑结构来驱动功率MOSFET,两只功率MOS-FET管在驱动变压器的作用下交替导通给灯管提供电流,开关频率由LC共振频率决定。这种电路存在着以下缺点:(1)电路本身不能自启动,通常要在低侧功率MOSFET管栅极加上双向触发二极管才能在电路接通瞬间触发低侧功率MOSFET管;(2)驱动变压器限制了电子镇流器的小型化;(3)驱动变压器的生产成本高。 采用IR215×系列控制集成电路取代传统的变压器驱动方式可克服上述缺点。IR215×系列芯片为高压、高速功率MOSFET或IGBT驱动集成电路,可驱动高侧和低侧MOSFET或IGBT,能够提供高达600V的直流偏置电压,具有自振荡或 相似文献
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基于半桥拓扑结构的特点,得出了MOS管驱动电路的基本要求,重点分析了MOS管驱动电路各分电路的设计参数,实验验证了驱动电路的合理性. 相似文献
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《Microelectronics Journal》2015,46(10):923-927
In this paper, pixel circuit using mirroring structure with Indium–Gallium–Zinc oxide (IGZO) thin film transistors (TFTs) for active matrix organic light emitting diode (AMOLED) display is proposed. This pixel circuit consists of only four TFTs, and one capacitor. Due to the mirroring structure, characteristic of the driving TFT can be precisely sensed by the sensing TFT, which is deployed in a discharging path for gate electrode of the driving TFT. This discharging process is strongly dependent on threshold voltage (VT) and effective mobility of the sensing TFT. Circuit operating details are discussed, and compensation effects for threshold voltage shift and mobility variations are verified through numerical derivation and SPICE simulations. Furthermore, compared with conventional schematics, the proposed pixel circuit might have much simplified external driving circuits, and it is a promising alternative solution of high performance AMOLED display. 相似文献
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A new a-Si:H TFT pixel circuit compensating the threshold voltage shift of a-Si:H TFT and OLED for active matrix OLED 总被引:1,自引:0,他引:1
Jae-Hoon Lee Ji-Hoon Kim Min-Koo Han 《Electron Device Letters, IEEE》2005,26(12):897-899
We propose a new hydrogenated amorphous silicon thin-film transistor (a-Si:H TFT) pixel circuit for an active matrix organic light-emitting diode (AMOLED) employing a voltage programming. The proposed a-Si:H TFT pixel circuit, which consists of five switching TFTs, one driving TFT, and one capacitor, successfully minimizes a decrease of OLED current caused by threshold voltage degradation of a-Si:H TFT and OLED. Our experimental results, based on the bias-temperature stress, exhibit that the output current for OLED is decreased by 7% in the proposed pixel, while it is decreased by 28% in the conventional 2-TFT pixel. 相似文献
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This paper presents a new poly-Si pixel circuit employing AC driving mode for active matrix organic light-emitting diode (AMOLED) displays. The proposed pixel circuit, which consists of one driving thin-film tran- sistor (TFT), three switching TFTs, and one storage capacitor, can effectively compensate for the threshold voltage variation in poly-Si and the OLED degradation. As there is no light emission, except for during the emitting period, and a small number of devices used in the proposed pixel circuit, a high contrast ratio and a high pixel aperture ratio can be easily achieved. Simulation results by SMART-SPICE software show that the non-uniformity of the OLED current for the proposed pixel circuit is significantly decreased (〈 10%) with an average value of 2.63%, while that of the conventional 2T1C is 103%. Thus the brightness uniformity of AMOLED displays can be improved by using the proposed pixel circuit. 相似文献
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具有顶部发光结构的AMOLED交流驱动电路 总被引:1,自引:1,他引:0
A new voltage programmed pixel circuit with top emission design for active-matrix organic lightemitting diode(AMOLED) displays is presented and verified by HSPICE simulations.The proposed pixel circuit consists of five poly-Si TFTs,and can effectively compensate for the threshold voltage variation of the driving TFT.Meanwhile,the proposed pixel circuit offers an AC driving mode for the OLED by the two adjacent pulse voltage sources,which can suppress the degradation of the OLED.Moreover,a high contrast ratio can be achieved by the proposed pixel circuit since the OLED does not emit any light except for the emission period. 相似文献
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基于低温多晶硅薄膜晶体管的AMOLED交流像素电路 总被引:1,自引:1,他引:0
This work presents a new voltage programmed pixel circuit for an active-matrix organic light-emitting diode(AMOLED) display.The proposed pixel circuit consists of six low temperature polycrystalline silicon thinfilm transistors(LTPS TFTs),one storage capacitor,and one OLED,and is verified by simulation work using HSPICE software.Besides effectively compensating for the threshold voltage variation of the driving TFT and OLED,the proposed pixel circuit offers an AC driving mode for the OLED,which can suppress the degradation of the OLED.Moreover,a high contrast ratio can be achieved by the proposed pixel circuit since the OLED does not emit any light except for the emission period. 相似文献
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KeeChan Park Jae-Hong Jeon YoungIl Kim Jae Beom Choi Young-Jin Chang ZhiFeng Zhan ChiWoo Kim 《Solid-state electronics》2008,52(11):1691-1693
An active-matrix organic light-emitting diode (AMOLED) display based on the polycrystalline silicon backplane technology has been fabricated that employs a new pixel circuit to compensate for the variation in the threshold voltage of the thin film transistors (TFT). The new pixel circuit also copes with the voltage drop in the supply line and a very high contrast ratio can be achieved. The uniformity of the new AMOLED display is remarkably improved compared with the basic two-TFT pixel structure, and it can be readily applied in the mass production of commercial AMOLED displays. 相似文献
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Functional Pixel Circuits for Elastic AMOLED Displays 总被引:1,自引:0,他引:1
Servati P. Nathan A. 《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》2005,93(7):1257-1264
While fabrication of active matrix organic LED (AMOLED) displays on plastic substrates continues to face technological challenges, stable electrical operation of thin-film transistor (TFT) pixel circuits under mechanical stress induced by substrate bending remains a critical issue. This paper investigates strain-induced shifts in hydrogenated amorphous silicon TFT characteristics and the compound impact on TFT circuit behavior. Measurements show that the magnitude of the shifts is determined by the direction of current flow in the TFT with respect to the bending stress orientation as well as bias conditions. Physically based compact models are developed that relate device characteristics to material behavior for design and optimization of AMOLED pixel circuits that can maintain immunity to bending stress. In particular, current mirror-based pixel circuits are presented that compensate for the long term threshold voltage shift and instantaneous strain-induced shifts in device characteristics. 相似文献
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Ya-Hsiang Tai Bo-Ting Chen Yu-Ju Kuo Chun-Chien Tsai Ko-Yu Chiang Ying-Jyun Wei Huang-Chung Cheng 《Display Technology, Journal of》2005,1(1):100-104
A new pixel circuit design for active matrix organic light-emitting diode (AMOLED), based on the low-temperature polycrystalline silicon thin-film transistors (LTPS-TFTs) is proposed and verified by SPICE simulation. Threshold voltage compensation pixel circuit consisting of four n-type TFTs, one p-type TFT, one additional control signal, and one storage capacitor is used to enhance display image quality. The simulation results show that this pixel circuit has high immunity to the variation of poly-Si TFT characteristics. 相似文献
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本文对一种LTPS-TFT AMOLED电压型阈值电压(V_(th))补偿像素电路进行了理论研究,分析了影响V_(th)补偿效果的主要因素。电路的补偿效果主要由驱动TFTV_(th)的获取精度和随后的保持精度决定。在V_(th)获取过程中,相关误差主要由驱动TFT转移特性电流对存储电容充电的充电率不足产生;在显示信号与V_(th)叠加过程中,与V_(th)保持节点连接的电容增量等因素会造成V_(th)保持精度的损失。根据分析的结果,本文解释了高分辨率像素电路补偿效果下降的原因。 相似文献
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A New Poly-Si TFT Current-Mirror Pixel for Active Matrix Organic Light Emitting Diode 总被引:1,自引:0,他引:1
《Electron Device Letters, IEEE》2006,27(10):830-833
A new poly-Si thin-film-transistor (TFT) current-mirror-active-matrix-organic-light-emitting-diode (AMOLED) pixel, which successfully compensates for the variation of the threshold voltage as well as mobility in the excimer laser annealed poly-Si TFT pixel, is designed and fabricated. The OLED current$(I_ OLED)$ of the proposed pixel does not depend on the operating temperature. When the temperature of pixel is increased from 27$^circhboxC$ to 60$^circhboxC$ , the$I_ OLED$ of the new pixel circuit composed of four TFTs and one capacitor increases only about 1.5%, while that of a conventional pixel composed of two TFTs and one capacitor increases about 37%. At room temperature, nonuniformity of the$I_ OLED$ in the proposed circuit was also considerably suppressed at around 9%. We have successfully fabricated a 1.2-in AMOLED panel$(hbox96 times hbox96 times hboxred green blue)$ to evaluate the performance of the proposed pixel. A troublesome residual image caused by the hysteresis phenomenon of the poly-Si TFT was almost eliminated in the proposed AMOLED panel as a result of current programming. 相似文献