TAS3308用于音频片上系统方案

TI 公司的TAS3308 是用于DTV音频系统的音频片上系统（SOC），包括有模拟合数字音频接口。对于模拟输入和输出，TAS3308有10个复接的立体声输入和一个立体声ADC与三个立体声PWM输出，对于数字输入和输出，TAS3308有三个I2S输入和两个I2S输出，其中一个I2S输出可配置成S/PDIF编码的PCM数据。本文介绍了TAS3308的主要特性，方框图以及应用电路。

TAS3308 is an audio system-on-a-chip (SOC) designed for digital TV audio systems and mini/micro component applications. It includes analog and digital audio interface. For analog input and output the TAS3308 has ten multiplexed stereo inputs with one stereo ADC and three stereo PWM outputs. For digital input and output the TAS3308 has three I2S inputs and two I2S outputs. One I2S output can also be configured to be S/PDIF encoded PCM data.

主要特性：
Audio Input/Output
Up to Three Synchronous Serial Audio Inputs (6 Channels)
Up to Two Synchronous Serial Audio Outputs (4 Channels)
Left, Right and I2S Output Data Formats: 16-, 20-, or 24-Bit Data
Left, Right and I2S Output Data Formats: 16-, 20-, or 24-Bit Data
64 × Fs Bit Clock Rate
24.576-MHz XTAL Input for Master Clock Modes and Clock Auto Detection
Slave Mode 256, 384, or 512 × Fs MCLKIN With Automatic Clock Rate Detection
Slave Mode 32-, 44.1-, and 48-kHz Fs With Auto Sample Rate Detection
Master Mode — 48-kHz Fs 10 Multiplexed Stereo Analog Inputs Selectable Into One Stereo ADC. ADC Maximum Input Level: 1 Vrms SE
Three Stereo Differential PWM Outputs
High-Quality DNR 100-dBA (Typical) ADC Channel Performance (2 Channels) With Master Mode Clock
High-Quality DNR 105-dBA (Typical) PWM Channel Performance (6 Channels)
One Single-Ended Analog Stereo Line Driver Output With 1 of 10 Selectable Inputs, 10-k ohm, 100=pF Drive Capability (Maximum Output Level: 1 Vrms)
Line-Out Supports Left/Right, Left/Left, and Right/Right Combinations
Audio Digital Signal Processor
Programmable Functionality
135-MHz Operation
48-Bit Datapath With 76-Bit Accumulator
Hardware Single Cycle Multiplier (28 × 48)
Two Memory Loads and One Memory Store Per Cycle
Usable 1K Words Data RAM (48 Bit) and Usable 1K Coefficient RAM (28 Bit)
3.25K Words Instruction Program RAM (2.8K Words Available)
360 mS at 48 KHz, 17,408 Words 24 Bit Delay Memory
PWM Features
Proven PurePath Digital? Technology
Fourth-Order Chaotic Noise Shaper With Non-Linear Correction
High-Quality DNR 105 dBA (Typical) PWM Performance
Click and Pop Minimizing at Power Up/Down Using TI Patented Technology
General Features
Easy-to-Use Control Interface
I2C Serial Control Master and Slave Interface
Control Interface Operational Without External MCLK Input
Single 3.3-V Power Supply
Integrated Regulators
100-Pin TQFP Package
M8051 Device Controller
Auto Clock and Serial Data Rate Detection and Automatic Device Configuration Without Audible Artifacts

The TAS3308 comprises nine functional blocks.
Analog input/MUX/stereo ADC
Three stereo PWM output for speaker/headphone/stereo
Line driver outputs
Clock, digital PLL, analog PLL, serial data interface, and auto-detect system
Serial control interface/device control
Audio DSP – digital audio processing
8051 device controller
Power supply
Internal references

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图1. TAS3308方框图

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图2. TAS3308应用电路图