D类功放多功能隔离驱动控制电路的设计  

Design of Multi-Function Isolated Drive Control Circuit for Class D Power Amplifier

作　　者：严添明[1] 严艳 YAN Tianming;YAN Yan(College of Information and Engineering,Liming Vocational University,Quanzhou,Fujian 362000,China;School of Information Engineering,Quanzhou Ocean Institute,Quanzhou,Fujian 362700,China)

机构地区：[1]黎明职业大学信息与工程学院,福建泉州362000 [2]泉州海洋职业学院信息工程学院,福建泉州362700

出　　处：《自动化应用》2024年第19期167-170,共4页Automation Application

基　　金：泉州市自然科学基金(校(院)地协同创新专项)“1bitADC技术通用D类音频功率放大器的研制”(Z【2014】0222)。

摘　　要：为解决现有D类功放静态损耗、背景噪声、抗干扰以及开机软启动和爆破声的问题,设计一款多功能隔离驱动控制电路。采用隔离检测电路对大功率电源电压进行隔离检测,产生欠压保护控制信号Vdc;采用精密全波整流电路检测有无音频输入,产生控制信号Vsc,采用集成运放构成施密特触发器,将有无音频输入控制信号Vsc与欠压保护控制信号Vdc进行逻辑线与,产生施密特触发器的触发控制信号Vc,决定施密特触发器输出的Voc状态,控制H桥隔离驱动电路工作状态,保证大功率电源在空载条件下安全启动;采用超低值电阻对脉动直流电流进行隔离检测放大,产生过流保护控制信号Iovc,叠加到斯密特触发器门限电压,迫使斯密特触发器输出Voc为高电平,关断H桥隔离驱动电路,实现过流或短路无触点保护控制;采用RC延迟电路对Voc进行延时适时控制,降低爆破声干扰,使整个系统达到了完美的效果,效率提高到95%以上,谐波失真大幅度降低,小于0.05%。In order to solve the problems of static loss,background noise,anti-interference,automatically startup and popping sound of the existing class D power amplifier,we designed a multifunctional isolated drive control circuit.It uses the isolation detection circuit to detect the high power supply voltage and generate the under voltage protection control signal Vdc.The circuit simultaneously employs a precision full-wave rectifier circuit to detect the presence of the control signal Vsc generated by the audio input.Additionally,it utilizes an integrated operational amplifier to form a Schmitt trigger,enabling the generation of the trigger control signal Vc based on whether there is an audio input control signal Vsc or an undervoltage protection control signal Vdc.This determines the state of Voc in the Schmitt trigger output,controls the operation of the H-bridge isolated drive circuit,and ensures safe startup of high power supply under no-load conditions.The pulsating DC current is isolated and amplified by using ultra-low value resistance.It generates the overcurrent protection control signal Iovc,superimposed to the Schmitt trigger threshold voltage,and then forces the Schmitt trigger to output Voc to a high level,and finally shuts off the H-bridge isolation drive circuit to realize the overcurrent or short circuit contact-free protection control.The RC delay circuit is utilized for timely and precise control of Voc,effectively reducing noise interference.As a result,the overall system achieves optimal performance with an efficiency increase to over 95%and a significant reduction in harmonic distortion to less than 0.05%.

关 键 词：电流隔离检测 电压隔离检测 隔离驱动控制 电路设计 

分 类 号：TN912[电子电信—通信与信息系统]