TI(NS) LM48901四路音频D类功率放大方案
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 = 8Ω, THD+N ≤10%时的输出功率为1.7W ,RL = 4Ω, 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 National’s proprietary spatial sound processor to create an enhanced sound stage for portable multimedia devices. The Class D output stages feature National’s edge rate control (ERC) PWM architecture that significantly reduces RF emissions while preserving audio quality and efficiency.
The LM48901’s 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.
The LM48901 is configured through an I 2C compatible interface and is capable of delivering 2.8W/channel of continuous output power into an 4Ω load with less than 10% THD+N. A 2.1 mode pairs two output drivers in parallel, increasing current drive for 4Ω loads.
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