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大功率高保真音座及其放声系统的过流保护常州无线电总厂王伟民高保真音座一般都采用OCL电路、双电源供电、输出功率大。用于功率放大的功放块和放声系统大都价格昂贵。因此,如何对功放和音箱进行保护,一直是专业音响工作者和广大业余爱好者考虑的问题。笔者在音响电... 相似文献
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本文以TI公司的TDA2030A为核心器件构成高保真声频放大器的功率放大器部分,推动扬声器系统放音,从而构建一个输出功率足够大、谐波失真和互调失真又很低、频率特性平坦的有源音响。 相似文献
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自从出现了象CD(激光唱片)和PCM(数码调制)一类的高保真产品。录象机产品中也出现了高保真录象机这种重视音质的产品。使人感到已进入声频和视频时代。声源的音质一高,放音系统的频率特性就有必要进行 相似文献
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以TI公司的TDA2030A型电路为核心器件构成高保真声频放大器的功率放大器部分,推动扬声器系统放音,构建一种输出功率足够大、谐波失真和互调失真很低、频率特性平坦的有源音响。 相似文献
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美国国家半导体公司推出的新型低压音频功率放大器具有优良的性能,清晰和强劲的声音及引脚小距离,适用于计算机、移动电话和其他的便携式音频产品。该放大器属工业标准组织BOOOMER系列,具有较大输出功率,低电压高保真声音,可用于各种视听产品的音频功率放大。此外,性价比高,0.7μA超低的待机电流与其专利“爆炸声和卡嗒声”消除技术及其内部过热保护电路,可延长便携式收音 相似文献
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在高保真音响技术或立体声放音技术中,功率放大器是一个重要的部件.近年来,在功率放大电路方面有新的发展,国外提出了许多新型的高保真功率放大器线路.本文旨在对这些新型电路进行介绍与分析.众所周知,在功率放大器中,人们广泛采用OTL或OCL功率放大电路.图1是典型的OCL电路的基本形式,它可以看作推挽形式的射极跟随器.其工作状态通常可分为甲类、甲乙类、乙类等等.由于这种功率放大电路在提高效率(因而可以相对地增大输出功率)和减少失真(这是高保真度所要求的)之间,往往存在着矛盾.也就是说,当工作在甲类时,它具有非线性失真小的优点,亦即保真度高,但是它的缺点是效率很 相似文献
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A monolithic quad audio power amplifier which reduces power dissipation by 45% with a music signal compared to a standard class-AB amplifier is described. A new two-stage operational amplifier, capable of providing high output current, is used for each one of eight power amplifiers. In a bridge configuration, a common-loop mode control is performed exploiting a sample-and-hold circuit. A multipower bipolar-CMOS-DMOS (BCD) technology is employed with a push-pull rail-to-rail output stage and a low-loss power switch. Experimental results are presented 相似文献
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Based on the difference close-loop feedback technique and the difference pre-amp, a high efficiency PWM CMOS class-D audio power amplifier is proposed. A rail-to-rail PWM comparator with window function has been embedded in the class-D audio power amplifier. Design results based on the CSMC 0.5 μm CMOS process show that the max efficiency is 90%, the PSRR is -75 dB, the power supply voltage range is 2.5-5.5 V, the THD+N in 1 kHz input frequency is less than 0.20%, the quiescent current in no load is 2.8 mA, and the shutdown current is 0.5 μA. The active area of the class-D audio power amplifier is about 1.47 × 1.52 mm2. With the good performance, the class-D audio power amplifier can be applied to several audio power systems. 相似文献
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A dual mode charge pump to produce an adaptive power supply for a class G audio power amplifier is presented.According to the amplitude of the input signals,the charge pump has two level output voltage rails available to save power.It operates both in current mode at high output load and in pulse frequency modulation (PFM) at light load to reduce the power dissipation.Also,dynamic adjustment of the power stage transistor size based on load current at the PFM mode is introduced to reduce the output voltage ripple and prevent the switching frequency from audio range.The prototype is implemented in 0.18μm 3.3 V CMOS technology.Experimental results show that the maximum power efficiency of the charge pump is 79.5%@ 0.5x mode and 83.6%@ lx mode.The output voltage ripple is less than 15 mV while providing 120 mA of the load current at PFM control and less than 18 mV while providing 300 mA of the load current at current mode control.An analytical model for ripple voltage and efficiency calculation of the proposed PFM control demonstrates reasonable agreement with measured results. 相似文献
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通过对当前计算机电源技术中广泛使用的多相PWM开关电源和单相开关电源原理的阐述,并比较了在音频功放中应用的优缺点,并从技术上分析了多相开关电源对大功率功放的供电品质改善的原因。 相似文献
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一种超低功耗放大器的设计 总被引:1,自引:1,他引:0
设计了一种集成于电源管理芯片内部的超低功耗运算放大器电路。采用HSPICE,对电路进行模拟仿真,并与传统放大器电路进行了比较。结果表明,该电路具有超低静态电流和超低功耗的特点。 相似文献
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CMOS PWM D类音频功率放大器的过流保护电路 总被引:1,自引:0,他引:1
基于Class-D音频功率放大器的应用,采用失调比较器及单边迟滞技术,提出了一种过流保护电路,其核心为两个CMOS失调比较器。整个电路基于CSMC0.5μmCMOS工艺的BSIM3V3Spice典型模型,采用Hspice对比较器的特性进行了仿真。失调比较器的直流开环增益约为95dB,失调电压分别为0.25V和0.286V。仿真和测试结果显示,当音频放大器输出短路或输出短接电源时,过流保护电路都能正常启动,保证音频放大器不会受到损坏,能完全满足D类音频放大器的设计要求。过流保护电路有效面积为291μm×59.5μm。 相似文献
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本文论述音频放大器的发展过程和当前出现的数字音频功率放大器的国内外现状。通过此文,以引起我国广播电视、电影等专业单位对这一新鲜事物的关注。使得音频放大器这个盲区也能进入数字化时代。 相似文献
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Carrier Distortion in Hysteretic Self-Oscillating Class-D Audio Power Amplifiers: Analysis and Optimization 总被引:1,自引:0,他引:1
An important distortion mechanism in hysteretic self-oscillating (SO) class-D (switch mode) power amplifiers-carrier distortion-is analyzed and an optimization method is proposed. This mechanism is an issue in any power amplifier application where a high degree of proportionality between input and output is required, such as in audio power amplifiers or xDSL drivers. From an average-mode point of view, carrier distortion is shown to be caused by nonlinear variation of the hysteretic comparator input average voltage with the output average voltage. This easily causes total harmonic distortion figures in excess of 0.1-0.2%, inadequate for high-quality audio applications. Carrier distortion is shown to be minimized when the feedback system is designed to provide a triangular carrier (sliding) signal at the input of a hysteretic comparator. The proposed optimization method is experimentally proven in an audio power amplifier leading to THD figures that are comparable to the state of the art. Experimental hardware is a hysteretic SO bandpass current-mode-controlled single-ended audio power amplifier capable of 45 W into 8 Omega or 80 W into 4Omega from a plusmn34 V supply with less than 0.03% THD from 100 Hz to 6.7 kHz. Carrier distortion is shown to account for this limitation in THD performance. 相似文献
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为了解决红外光通信存在传输方向单一和消耗功率高问题,设计基于嵌入式技术的超低功耗红外光通信系统,系统单片机使用改进型STM32,将超低功耗红外发射装置嵌入到红外光通信系统中,该装置通过固定载波频率将输入音频信号,通过发送校准模式和音频传输模式调制为高频方波信号后,采用红外光管向外发射信号,并在电路中增加功率负载电流实现限流,降低红外光发射电路功耗。红外接收装置通过共射级放大电路接收信号,采用脉冲宽度调制(PWM)调制信号,实现信号高质量、低功率传输。红外通信模块实现红外发射装置和接收装置间信号的双向传输。系统采用保护驱动模式、中断模式与用户模式的红外通信协议栈,最大程度降低系统通信能耗,提高系统通信效率。实验结果表明:该系统能够实现信号和温度信号的有效传输,在休眠和正常运行时的功耗均较低,误码率低,是一种功率消耗低、通信质量高的红外光通信系统。 相似文献