Design Of High Efficiency Filterless Class D Audio Power Amplifier IC

Compared with the traditional audio power amplifier, the filterless ones have some advantages, such as lower distortion, lower power consumption and smaller size, especially the theoretical efficiency of it can be100%, as well the actual efficiency has reached80%, far more than any other ones. So that Class D audio power amplifier has an irreplaceable position.The primary works in this thesis are presented as follows:(1)Based on the analysis of Class D amplifier structure and principle, Class D amplifier IC with on-Chip Power MOSFETs is designed.Which has an optimized PWM output architecture, whithout a output LC filter.This technology can simplifying the design,reduce the area of the circuit and can improve power efficiency at the same time.(2) Completed the circuit design, shematic drawing and simulation of main units.Such as:pre-amplifier,oscillator,PWM module, bias circuit and output module. Especially in the bias circuit includes a bandgap reference circuit can be used as on-chip power supply, thereby reducing static power Class D amplifier improves the efficiency of Class D power amplifier;(3) Completed the chip layout design with specific process. Attention symmetry and matching to meet the parameters of the indicator.Completed the entire IC design with CSMC0.35μ m mixed CMOS process.The supply voltage of the IC is from2.5V to5.5V, the internal operating frequency is200KHz. Simulated the circuit with Cadence and Huada Aether EDA software. The result suggests that the design has accomplished its requests.