The Design Of A Novel Bridge Mode CMOS Audio Power Amplifier With Low Power Consumption

With the vigorous development of the consumer electronics market and the increasing development of the semiconductor technology, power amplifier, as a most widely used component in such products, has attracted more and more attention and is playing an important role in integrated circuits and SOC system at present. As a matter of fact, CMOS audio power amplifier has become the mainstream because of its low-power consumption, low-cost, high-quality output etc.This paper begins from the basic theory research of audio power amplifier, gives the appropriate technical indicators in the light of market demand and applications. A top-down design order is flowed from the system mode selection to the cell circuit module design and simulation. Finally, a novel bridge mode CMOS audio power amplifier with low power consumption is designed, which is used in mobile phones and other portable communication device applications. The chip is capable of delivering 1 watt of continuous average power to an 8? BTL load with less than 1% distortion (THD+N) from a 5VDC power supply.Compared to the classic single-ended configuration, the bridge mode can provide differential drive to the load, thus doubling output swing for a specified supply voltage, at the same time , times the output power by four , compared to a single-ended amplifier under the same conditions. The folded cascode structures, AB class of feed-forward type push-pull output stage are used in the amplifier design, at the same time ,external current source power supply and low-voltage cascode current mirror structure are there to achieve a larger output swing and good frequency characteristics. Control circuit section consists of temperature protection module, POP-CLICK suppression module and shutdown control module.Cadence Spectre tools are used to give a good modeling and simulation of the whole system based on CSMC CMOS 0.5μm1P2M technology,and the layout is finished with Cadence Virtuoso Layout XL tool. It is confirmed that the performance of the audio power amplifier system meets the design target well with the simulation results.