原标题：TI PCM186x 110dB立体声音频模数转换(ADC)解决方案

　　TI公司的PCM186x系列是音频前端器件,集成了许多系统级功能,可以替代某些DSP功能,采用新的方法集成音频功能,很容易和欧洲Ecodesign兼容,并开发出具有高性能终端产品和降低成本,通用的模拟麦克风输入,8个带MUX和PGA的模拟输入,4x数字麦克风输入,硬件可编程增益放大器和软件可编程增益放大器,主要用在家庭影院和TV,汽车音响,蓝牙扬声器以及麦克风阵列处理器.本文介绍了PCM186x系列主要特性和框图,系统配置框图和评估模块PCM186xEVM (EVM)特性,电路图,材料清单和PCB元件布局图.

　　The PCM186x family of audio front-end devices takes a new approach to audio-function integration to ease compliance with European Ecodesign legislation while enabling high-performance end products at reduced cost. With no need for a 5-volt supply or an external programmable-gain amplifier, smaller, smarter products are feasible at reduced cost.

　　The PCM186x highly flexible audio front end supports input levels from small-mV microphone inputs all the way to 2.1VRMS line Inputs without external resistor dividers. The PCM186x family integrates many system-level functions that assist or even replace some DSP functions.

　　All these features are available using a single 3.3V power supply. An integrated bandgap voltage reference provides excellent PSRR, so that a dedicated analog 3.3V rail may not be required.

　　PCM186x系列主要特性:

　　Universal Analog Mic Input, 2.1VRMS Full Scale

　　8 Analog Inputs with MUX and PGA

　　Analog pre-mix function before PGA/MUX

　　Single Ended, Pseudo-Differential or Differential Inputs with Mic Bias

　　4x Digital Microphone Inputs

　　Up to 4 Mono ADC channels (PCM1865)

　　Hardware Control (PCM1861)

　　I2C or SPI Control (PCM1863/5)

　　H/W Programmable Gain Amplifier

　　Fixed Mic Pregain select : 20, 32dB (Analog)

　　S/W Programmable Gain Amplifier

　　Integrated High Performance Audio PLL

　　Single 3.3V Supply for Analog and Digital

　　Additional 1.8V Core and Interface for lower power consumption

　　Power Dissipation at 3.3V: <85mW (PCM1861/3), <145mW (PCM1865)

　　’Energysense’ Audio Content Detector - for auto system wakeup and sleep

　　Master or Slave Audio Interface:

　　Mixer functionality:

　　Digital Mixer to mix ADC outputs and I2S synchronous inputs

　　Zero Crossing PGA Gain changes

　　Auto PGA Clipping Suppression Control

　　PCM186x系列主要应用:

　　• Home Theater and TV

　　• Automotive Head Units

　　• Bluetooth® Speaker

　　• Microphone Array Processors

　　图1. PCM186x系列内部框图

　　图2. PCM186x系列简化框图

　　图3. PCM186x系列系统配置框图

　　评估模块PCM186xEVM (EVM)

　　The PCM186xEVM (EVM) is an easy-to-use evaluation board for the PCM186x family of ADCs. Due to the pin-for-pin nature of the PCM186x family, any of the following part numbers can be used with this board; PCM1861, PCM1863, and PCM1865.

　　The PCM186xEVM (EVM) is an easy-to-use evaluation board for the PCM186x family of ADCs. Due to the pin-for-pin nature of the PCM186x family, any of the following part numbers can be used with this board; PCM1861, PCM1863, and PCM1865.

　　图4. 评估模块PCM186xEVM和USB-I2X板连接图

　　图5. 评估模块PCM186xEVM和USB-I2X板框图

　　评估模块PCM186xEVM材料清单: