K类音频功放的防破音控制系统  

Non-clipping control system for Class K audio power amplifier

作　　者：王绍清 叶春晖 胡养聪 

机构地区：[1]矽恩微电子厦门有限公司,福建厦门361005

出　　处：《电子技术应用》2016年第1期22-24,共3页Application of Electronic Technique

摘　　要：设计实现了一种可用于K类音频功放的防破音控制系统,通过自动检测输出削波失真调整系统增益,确保K类音频功放在较大的输入动态范围内,输出音频信号光滑无失真。确保K类音频功放在整个工作电压内保持低谐波失真,且保持恒定输出功率。采用0.5μm CMOS工艺实现了集成这种防破音控制系统的2.0 W单声道K类音频功放。测试结果显示,在3.3 V^4.2 V电源电压范围、增益设置为24 d B、4Ω喇叭负载下,该K类音频功放能够在0~1.2 V_(rms)的动态输入范围内保持低谐波失真(THD+N)<0.5%,恒定无削波输出功率2.0 W。Non-clipping control system for Class K audio power amplifier application is presented.The system can automatically de-tect the distortion of output signal and adjust gain of the Class K audio power amplifier accordingly in order to avoid clipping in a large input dynamic range.Ensure the Class K audio amplifier can keep low THD ＋ N and fix output power within the whole power supply range.A Class K audio amplifier that integrated with the non-clipping control system was implemented in 0.5 μm CMOS process.The measurement result shows that at 3.3 ~ 4.2 V power supply,24 d B gain setting and 4 Ω speaker loading the amplifier can keep（ THD ＋ N）〈0.5 % with the fix output power of 2.0 W within the input signal range of 0 ~ 1.2V_（rms）.

关 键 词：防破音控制 K类音频功放 输入动态范围 总谐波失真 

分 类 号：TN402[电子电信—微电子学与固体电子学]