摘要
基于0.8μm BCD工艺完成了一种具有高转换效率的20W×2立体声集成音频功率放大器.该放大器可在18V电源电压下以全桥输出的方式向8Ω负载提供超过20W的功率,其转换效率可达85%以上.介绍了功率输出级、过流保护电路以及高性能轨-轨比较器的设计,并基于横向双扩散MOSFET器件结构讨论了功率输出器件寄生效应对输出电压波形失真的影响.最后给出了所设计的D类音频功率放大器的测试结果.
This paper presents a 20W × 2 class-D audio power amplifier with high efficiency in a 0.8μm BCDMOS process. The ampli- fier is capable of driving 2 × 80 loads from a 18V power supply at more than 85% power efficiency,and its maximum output power is more than 20W × 2. The circuit detail of the output stage,over-current protection,and rail-to-rail comparator are also presented. Through analysis of the LDMOSFET cross section, the impact of the parasitical effect on the distortion of the output is discussed. Finally, the experimental results of this work are presented.
基金
国家自然科学基金(批准号:60476046
60676009)
教育部博士点基金(批准号:20050701015)
国家杰出青年科学基金(批准号:60725415)资助项目~~
关键词
D类功率放大器
全桥
过流保护
轨-轨比较器
class-D power amplifier
full-bridge
over-current protection
rail-to-rail comparator
