带有过温保护功能的低功耗音频功率放大器  

Low power consumption audio power amplifier with over-temperature protection function

作　　者：廖涵章 汪洋 金湘亮 LIAO Hanzhang;WANG Yang;JIN Xiangliang(School of Physics and Optoelectronics,Xiangtan University,Xiangtan 411105,China;Microelectronics and System Integration Hunan Engineering Laboratory,Xiangtan 411105,China;School of Physics and Electronics,Hunan Normal University,Changsha 410081,China;Super ESD Microelectronics Technology Co Ltd,Changsha 410100,China)

机构地区：[1]湘潭大学物理与光电工程学院,湖南湘潭411105 [2]微光电与系统集成湖南省工程实验室,湖南湘潭411105 [3]湖南师范大学物理与电子科学学院,湖南长沙410081 [4]湖南静芯微电子技术有限公司,湖南长沙410100

出　　处：《传感器与微系统》2020年第6期100-102,106,共4页Transducer and Microsystem Technologies

基　　金：国家自然科学基金资助项目(61704145,61774129,61827812,61601395);长沙市科技计划项目(KQ1703001)。

摘　　要：设计了一种用于驱动耳机的AB类音频功率放大器芯片。针对音频功放耗电快和芯片温度过高而损坏的问题,通过减小差分输入对尾电流源的大小,让MOS管工作在亚阈值区,降低了电路功耗;通过增加过温保护电路,对芯片进行有效的温度保护。Cadence仿真结果表明,该电路获得了较高的峰值负载功率与静态功耗比值为21. 2,具有较高的电源效率。过温保护电路在136℃时开启过温保护,温度回落到80℃时核心放大电路重新开启,电路具有56℃的温度滞回区间。测试结果表明,电路可在负载为16Ω时工作,提供92. 4 m W的功率。芯片面积在0. 5μm标准CMOS工艺下为0. 893 mm^2。A class AB audio power amplifier chip for driving headphones is designed.Aiming at the problems that fast power consumption of audio amplifier and chip damaged by high temperature,by reducing the size of the differential input pair of tail current source,the MOS tube is allowed to work in the sub-threshold region,reducing the circuit power consumption;temperature protection circuit is added to protect the chip effectively.Cadence simulation results show that the circuit achieves a high peak load power to quiescent power ratio of 21.2 and has high power efficiency.Over-temperature protection circuit open over temperature protection at 136℃.With the temperature dropps to 80℃,the core amplifier circuit restarts・Circuit has 56℃ temperature hysteresis interval.Test results show that,at the load of 16Ω,the circuit is capable of delivering 92.4 mW continuous average power.It occupies 0.893 mm^2 in a standard 0.5μm CMOS process.

关 键 词：音频功率放大器 AB类 过温保护 峰值负载功率与静态功耗比 

分 类 号：TN402[电子电信—微电子学与固体电子学]