
设计注意事项
With the continuing explosion of portable consumer audio devices ranging from MP3 Players/Recorders to smart phones with integrated audio capability, handheld GPS systems and many others, the required integrated audio feature set continues to challenge end-equipment manufacturers as well as IC designers.
Being portable typically implies that the devices are battery-operated and therefore system power consumption is a key concern.
Portable audio ICs for the consumer audio market include integrated audio codecs or audio ADCs and DACs for conversion between analog signals and digital data, headphone or speaker drivers for earpieces, headphones or built-in speakers, programmable DSPs for encoding/decoding compressed data in such formats as MP3, WMA or AAC, microcontrollers for handling system-level control and user interface functions, and wireless transceivers for transmission/reception of data over RF. The core subsystems include:
- DSP: Performs the audio/encode functions, executes post-processing algorithms like equalization and bass management and system related tasks like file management and the user interface control.
- Memory: Stores executing code and data/parameters.
- Peripheral Interface: Allows user to control I/Os and display.
- Audio CODEC: Interface with the phone lines, audio input, microphone, headphone, and speaker for digitizing the audio in the DSP. Newer generation TI audio codecs, such as the TLV320AIC3254, process sound with better audio quality and longer battery life.
- Power Conversion: Converts the battery power to run various functional blocks