ASIC Design And Implementation Of High Anti-Noise Audio Class-D Power Amplifier

The paper is based on the project"Theoretical Research and Design of Class-D Audio Power Amplifier with High Performance"and mainly discusses the principle of Class-D audio power amplifier.Firstly, the operating principles and performance characteristics of various audio PAs are analyzed. Then, the working principle and the controlling mode of Class-D audio power amplifier are introduced in detail. On the basis of expounding the key performances of Class-D audio power amplifier, a high anti-noise Class-D audio power amplifier has been designed in this paper.The designed IC is based on the half bridge topology, and consists of integrator, comparator, output stage and feedback. The continuous-time sigma-delta modulation (CT-SDM) technique with noise-shaping effect is utilized in this design. A self-oscillating modulator which occupies smaller chip area is obtained based on CT-SDM. Great protection circuits ensure the safety of the chip and fault restart. A programmable preset dead-time block which sets relevant dead-time in terms of different applications is integrated. Then, in the premise of the low distortion, the performance of the designed IC is well-balanced. Moreover, start and stop click noise is reduced. In this paper, we design and simulate every block of Class-D audio power amplifier, including integrator amplifier, programmable preset dead-time block, logic control block, bidirectional over-current protection circuits, click noise immunity block, and under-voltage protection block.The whole circuit is designed based on the 0.6μm BCD process. The simulation and the verification have completed by the EDA tools such as Cadence etc. According to the simulation results, the function and the performance of the whole circuit have met all the requirements.