双模式控制防失真K类音频功率放大器设计  

Design of class K audio power amplifier with dual mode control anti distortion

作　　者：王宇星[1] 

机构地区：[1]无锡科技职业学院,江苏无锡214028

出　　处：《电子技术应用》2016年第4期31-34,共4页Application of Electronic Technique

摘　　要：提出了一种具有双模式控制、防失真、超低EMI、内部集成升压电路的高效率音频功率放大器。系统可通过一线脉冲方式控制放大器工作在防失真模式或普通模式,其中防失真功能通过输出信号的大小自动调整增益实现。电路采用CSMC 0.5μm CMOS工艺实现,测试结果表明：在电源电压5 V、输出端接感性负载RL=8Ω＋33μH的条件下,该功放能够在0~3 V的信号输入范围内保持总谐波失真加噪声（THD＋N）仅为0.2%,最大输出功率2 W。该功率放大器在锂电池电压下降时也能持续提供2 W的输出功率,适合便携式产品的应用。A dual mode control, anti distortion, ultra low EMI, internal integrated boost circuit is designed to realize the high volume output high efficiency audio power amplifier. The system can be used to control the amplifier ＇ s work in the distortion mode or normal mode according to the size of the output signal, adjust the gain to achieve anti distortion function automatically. The circuit is realized by 0. 5 μm CMOS CSMC process. The test results show that ： under the condition of 5 V power supply voltage, load RL = 8 Ω ＋ 33 μH, the power amplifier can maintain the Total Harmonic Distortion ＋ Noise（ THD ＋ N） in 0. 2 % with the input signal range from 0 V to 3. 3 V, the largest output power is 2 W. The power amplifier can also provide 2 W output power when the lithium battery voltage drops which is suitable for the application of portable products.

关 键 词：音频功率放大器 防失真 PWM调制 总谐波失真 

分 类 号：TN722[电子电信—电路与系统]