D类音频功放芯片自恢复过流保护电路  

Self-recovering over current protection circuit for class-D audio power amplifier

作　　者：徐勇[1] 胡澄[1] 吴元亮[1] 赵斐[2] 关宇[1] 唐路[3] 

机构地区：[1]解放军理工大学理学院,江苏南京211101 [2]解放军理工大学指挥信息系统学院,江苏南京210007 [3]东南大学射频与光电集成电路研究所,江苏南京210096

出　　处：《解放军理工大学学报（自然科学版）》2012年第5期497-500,共4页Journal of PLA University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(61106024);教育部高等学校博士学科点专项科研基金资助项目(2009009120012)

摘　　要：针对高功率D类功放芯片使用过程中可能出现的短路操作导致芯片损坏的风险,设计并实现了一种具有自恢复能力的D类功放过流保护电路。在功放芯片输出管脚发生对地短路、对电源短路、或者2个输出管脚之间相互短路时,能够及时关闭功率电路输出以保护芯片不会损坏。芯片测试结果表明,5V/4Ω条件下,该D类功放输出最大功率2.75W,效率90%。过流保护电路工作正常,过流域值约为3A。较之其他电路方案,本方案的优点在于,当短路事件去除后,能够及时自动恢复正常输出,克服了传统保护方案需要芯片复位才能恢复正常工作的缺点。To avoid being damaged when class D power amplifier chip is applied in error,this paper presented a self-recovering over the current protection circuit in class-D audio power amplifier.The over current protection circuit would quickly shut down the output stages as soon as two output-pins short-circuit to power supply,ground or short-circuit to each other.The chip achieves a maximal power of 2.75W and maximal efficiency of 90% at a 4 Ω load when power supply voltage is 5V.The over current-threshold is 3A.The best advantage of this novel scheme is that it could help the chip to recover normal output automatically as the over-current removed,different from other conventional scheme which would recover normal output only through resetting the chip.

关 键 词：D类音频功率放大器 过流保护 互补型金属氧化物半导体 

分 类 号：TN402[电子电信—微电子学与固体电子学]