Design Of A High-performance Audio Power Amplifier

In recent years, integrated circuit (IC) industry has had a rapid development,especially the development of portable electronic products. The application of IChas penetrated into all areas of society including military. The boom of consumerelectronics drive the development and research of low-cost and low-powerintegrated circuit[1]. As the advance of technology, more and more poweramplification circuits adopt the integrated method to achieve. Audio power amplifieris a very important part of the field of power integrated circuits, and is widely usedin consumer electronic products. China is currently the world’s largest industry baseof consumer electronics. With the growing demand for audio amplification device,the electronic products will have a broader market[2]. Therefore, the research anddesign for the high-performance audio power amplifier has an important andpractical significance.Firstly, five different types of power amplifiers are introduced. The articledescribes in detail their working principle and characteristics, and then compares theadvantages and disadvantages of these types of amplifiers. In consideration ofefficiency, distortion and sound quality, finally we select class-AB structure as thestructure of our power amplifier.The chip is a four-channel BTL power amplifier for car audio applications. Theamplifier has sufficient voltage range (8～18V); has max instantaneous power for45W; has low total harmonic distortion, and THD is only0.007%under certainconditions; has selection functions for standby mode and mute mode; and hasinternal short-circuit protection, in exceptional circumstances, the power outputstage has been shut down to prevent its power output tubes and the speaker loadfrom damage.The chip uses the0.35μm BCD process to achieve. In Cadence Spectreenvironment, all the modules of the chip are put together to run simulation, and theresults meet the design requirements.