一种自适应滤波D类音频功率放大器设计  

Design of Class-D Audio Power Amplifier With adaptive filter

作　　者：王宇星[1] 

机构地区：[1]无锡科技职业学院,江苏无锡新锡路8号214028

出　　处：《电子技术（上海）》2015年第10期47-50,共4页Electronic Technology

摘　　要：设计了一个1.1W单通道自适应滤波的D类音频功率放大器,该功率放大器采用双边对称三角波作为载波的PWM调制方式,有效降低功放的总谐波失真度。测试结果表明:在5V电源电压下驱动4Ω负载,可提供1.1W的额定输出功率,效率高达90%。电路采用共模反馈的全差分放大输入设计具有高噪声抑制比,低静态电流与较强的抗电源干扰EMI的特点。Designed a 1.1 W single channel adaptive filter class D audio power amplifier, the power amplifier adopts the bilateral symmetrical triangle wave as the carrier PWM modulation mode, effectively reduce the total harmonic distortion of the power amplifier. The test results show that the drive 4 Ω load under 5v power supply voltage, can provide the rated output power of 1.1 W, efficiency is up to 90%. Circuit adopts full differential amplifier input common-mode feedback design with high noise rejection ratio, low static current and strong anti interference EMI characteristics.

关 键 词：D类音频功率放大器 效率 PWM调制 谐波失真 

分 类 号：TN722.75[电子电信—电路与系统]