摘要
基于NXP Class-D类TFA9810T芯片,实现一种具有立体声功能绿色能效模拟D类功率放大器设计,该音频放大器主要由全差分输入和全桥BTL输出结构的双通道功放和二阶巴特沃思滤波器构成。详细介绍模拟D类功放系统拓扑结构,PWM调制、输入和全桥输出、负反馈、LPF滤波器电路设计,重点探讨了死区校正、EMI抑制和PCB布局设计要素。仿真测试表明,供电电压15 V时,功放可向两个8Ω扬声器提供10 W×2输出功率,实际转换效率可达90%,总谐波失真小于7%,1 kHz正弦波音频输出无交越失真,无明显EMI干扰,功放壳体相对温升25℃。
This paper presents a 2 - channel stereo Class - D audio amplifier with green - efficiency based on the chip of TFA9810T made by NXP. The amplifier is composed of full differential input comparators and two full - bridge power stages and 2- stage butterworth. The key notes ＆ design of Class- D amplifier besides the system structure, PWM - modulation, input＆output stages, negative feedback and LPF stage are introduced in detail, especially the design notes of deadtime and EMI and how to routine PCB are analysed. The results of simulation and measurement show that the amplifier can deliver 10 W× 2 into 8 Ω loads at asymmetrical supply voltage 15V. The maximum convert efficiency of the amplifier is up to 90%. The THD＋N is less than 7%. The cross- distortion of the output wave with 1 kHz can not be found,EMI can not be observed during measuring,The temperature added on the surface of TFA9810T is 25 ℃.
出处
《现代电子技术》
2009年第11期179-184,共6页
Modern Electronics Technique
关键词
D类功放
绿色能效
全桥
电磁干扰
印制板
Class - D audio amplifier
green - efficiency
full - bridge
EMI
PCB
