Design of Multi-Function Isolated Drive Control Circuit for Class D Power Amplifier
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%.
current isolation detectionvoltage isolation detectionisolated drive controlcircuit design
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维普
