Design Of High Performance Class D Audio Amplifiers

Class D audio amplifier is a switching audio amplifier,the work of the power output stage MOS tube is fully turned on or completely off state,this state can improve the efficiency of the amplifier.Class D audio amplifier in theory can reach 100%efficiency,in fact,can reach 80%-95%.This makes these types of audio amplifiers more efficient than traditional audio amplifiers,so Class D amplifiers are often used in TVs or home audio devices.Based on the 0.35?m BCD process,a class D high-performance closed loop filterless class-D audio amplifier is designed in this dissertation,which aims to have high PSRR and THD,and uses Cadence software platform to design the circuit Design and simulation.The basic structure of the Class D audio amplifier used in this thesis mainly includes submodules such as modulator,gate drive circuit and power output stage.This article combines the benefits of open-loop and closed-loop architectures with a new class of digital input closed-loop class-D audio amplifier.The input signal of the structure is modulated by the modulator to control the driving circuit to drive the output stage output signal,and the output signal is fed back to the modulator input terminal from the feedback loop for correcting the non-linearity of the power supply ripple and the switching power stage.In this paper,the main performance parameters of the Class D amplifier are as follows,the power supply voltage input range 4.5-26V,all the following simulation are in the supply voltage of 24V,the input signal frequency 1kHz load 8?conditions;when the load output power of 1W,the total harmonic The THD of wave distortion is 0.1%.When the output power is 15W,the total harmonic distortion(THD)is 0.02%.When the frequency is 1kHz,the PSRR of the power supply is 70dB.The gain is 20dB and the frequency is 20Hz-22kHz.A-wt Filter noise Noise is 38.7?V;Efficiency is 85.7%;Layout area is 8.07mm~2.