基于微控制器与FPAA的音频均衡器设计-电路与系统专业论文.docx

摘要 摘要 I万方数据 I 万方数据 摘 要 音频均衡器作为常用的音效调节设备，使用非常广泛。目前，由电阻、电容和运 算放大器构建模拟电感，与阻容器件组合构成的模拟音频均衡器，存在正确调节难度 大、高档次音频均衡器整机体积大成本高、音频滤波稳定性差等不足；而基于数字滤 波技术的数字音频均衡器由于成本、价位较高主要应用于高档场合。另外，现代集成 电路设计和制造得到了突飞猛进的发展，基于开关电容技术的现场可编程模拟阵列 FPAA 技术取得了极大的发展，一些成熟的 FPAA 芯片也相继推出。因此，这里尝试 使用 AN221E04 FPAA 芯片来实现一个全新概念的调节简便、成本低的音频均衡器设 计。本文首先探讨 FPAA 技术及本文所使用的 FPAA 芯片 AN221E04 的特性，并在 滤波器设计理论的指导下，详细探讨基于 AN221E04 的开关电容滤波器设计规律；然 后，以四种常用滤波器方式和 2、4、6、8 等阶次设计各滤波器，同时对其频率响应 曲线进行仿真，并以比较设计的方式经过较大工作量的运算、推导与软件仿真，来比 较各种类、各阶次滤波器在音频均衡器滤波系统设计中的频率响应特性；最后，确定 使用基于 FPAA 技术的巴特沃兹开关电容滤波器来实现本文设计的音频均衡器滤波 系统，并利用多颗 FPAA AN221E04 芯片构建 FPAA 阵列，与 89S51 MCU 及 Serial EEPROM 构建一个音效调节参数实时静态和动态可调的音频均衡器。 关键词： 滤波器，音频均衡器， FPAA，MCU Abst Abstract II万方数据 II 万方数据 Abstract Audio equalizer is a common sound effect adjustment device, which has a broad application in audio field. Normally, analog audio equalizer is combined by resistors, capacitors and equivalent analog inductances; the equivalent analog inductance is constructed by resistors, capacitors and operation amplifier. On the one hand, the analog audio equalizer is hard to adjust properly, advanced analog audio equalizer needs high cost and volume, and the audio filter reliability is poor. On the other hand, the digital audio equalizer which based on digital filter technology, only get its application in some advanced situations. Because of its high cost and price. In addition, with the modern integrated circuit design and manufacture technology advance rapidly development, the (FPAA) field programmable analog array technology which based on S/C (switch capacitor) technology, has obtained an obvious development. Presently, several commercial FPAA integrated circuits are designed. Therefore, this paper tries to use AN221E04 FPAA chip to realize a new concept audio equalizer design. Because of the lacking information about the S/C FPAA technology, firstly, this paper discuss the S/C FPAA technology and the chip characteristic of AN221E04 which is used in this paper design.