TI(NS)LM48901四路音频D类功率放大方案

1、TI(NS)LM48901四路音频D类功率放大方案时间:2011年11月21日 字 体: 大 中 小关键词:消费类电子D类功率放大器TI公司TI(NS) 公司的LM48901是四路音频D类功率放大器,输出级采用前沿速率恐怖行动(ERC)PWM架构,能降低RF辐射而维持音频质量和效率,它的I2S接口和标准串行音频接口兼容,差分输入立体声ADC,平行输出模式,RL = 8, THD+N 10%时的输出功率为1.7W ,RL = 4, THD+N 10%时为2.8W (typ),而典型的THD+N为0.06%,主要用在便携式计算机,平板电脑,台式电脑,条形音箱,多媒体设备,MP3播放器附件和坞站.本

2、文介绍了LM48901主要特性和指标,音频放大器应用电路,通路音频放大器应用电路和I2C_EN/I2C_EX菊花链案例应用电路以及评估板主要特性.The LM48901 is a quad Class D amplifier that utilizes Nationals proprietary spatial sound processor to create an enhanced sound stage for portable multimedia devices. The Class D output stages feature Nationals edge rate contro

3、l (ERC) PWM architecture that significantly reduces RF emissions while preserving audio quality and efficiency.The LM48901s flexible I 2S interface is compatible with standard serial audio interfaces. A stereo differential-input ADC gives the device the ability to process analog stereo audio signals

4、.The LM48901 is configured through an I 2C compatible interface and is capable of delivering 2.8W/channel of continuous output power into an 4 load with less than 10% THD+N. A 2.1 mode pairs two output drivers in parallel, increasing current drive for 4 loads.Output short circuit and thermal overloa

5、d protection prevent the device from being damaged during fault conditions. Superior click and pop suppression eliminates audible transients on power-up/down and during shutdown. The LM48901 is available in space saving microSMD and LLP packages.LM48901 主要特性:Spatial Sound ProcessingI 2S Compatible I

6、nputDifferential-Input Stereo ADCEdge Rate Control Reduces EMI while Preserving Audio Quality and EfficiencyParalleled Output ModeShort Circuit and Thermal Overload ProtectionMinimum external componentsClick and Pop suppressionMicro-power shutdownAvailable in space-saving micro SMD and LLP packagesL

7、M48901 应用:LaptopsTabletsDesktop ComputersSound BarsMultimedia DevicesMP3 Player AccessoriesDocking StationsLM48901 主要指标:SNR (A-Weighted)87dBA (typ)Output Power/channel, PVDD = 5VRL = 8, THD+N 10%1.7W (typ)RL = 4, THD+N 10%2.8W (typ)THD+N0.06% (typ)Efficiency/Channel89% (typ)PSRR at 217Hz71dB (typ)Sh

8、utdown current1A (typ) 图1.LM48901典型音频放大器应用电路图2.LM48901通路音频放大器应用电路图3.LM48901 I2C_EN/I2C_EX菊花链案例应用电路The LM49801 evaluation board accepts three audio input formats: stereo differential analog, SPDIF, or I2S. Multiple boards are easily cascaded, increasing the number of channels. The LM48901 can also be configured as a 2.1 amplifier for stereo + subwoofer applications.The board is controlled though a Windows- and Mac OSX-compatible graphic user interface (GUI). The GUI configures the device, loads spatial coefficients, and provides a graphic equalizer. The board connects to a