原标题：ADI ADAU1777音频编译码器(CODEC)数字处理方案

　　ADI公司的ADAU1777是四输入和两输出的音频编译码器(CODEC),采用数字处理引擎来实现滤波,电平控制,信号电平监视和混合,集成了24位ADC和DAC.模拟和数字输入/输出1.8V-3.3V,DSP核工作电压1.1V-1.8V,I2C和SPI控制接口,主要用在降噪手持设备和耳机,蓝牙降噪手持设备和耳机,个人导航设备和数字照相机和摄像机.本文介绍了ADAU1777主要特性,功能框图,以及评估板EVAL-ADAU1777Z主要特性,框图,电路图,材料清单和PCB设计图.

　　The ADAU1777 is a codec with four inputs and two outputs that incorporates a digital processing engine to perform filtering, level control, signal level monitoring, and mixing. The path from the analog input to the DSP core to the analog output is optimized for low latency and is ideal for noise canceling headsets. With the addition of just a few passive components, a crystal, and an EEPROM for booting, the ADAU1777 provides a complete headset solution.

　　Note that throughout this data sheet, multifunction pins, such as SCL/SCLK, are referred to either by the entire pin name or by a single function of the pin, for example, SCLK, when only that function is relevant.

　　ADAU1777主要特性:

　　Programmable audio processing engine

　　Fast (up to 768 kHz) and slow processing paths

　　Biquad filters, limiters, volume controls, and mixing

　　Low latency, 24-bit ADCs and DACs

　　102 dB SNR (through PGA and ADC with A weighted filter)

　　108 dB combined SNR (through DAC and headphone with A weighted filter)

　　Serial port sampling rate from 8 kHz to 192 kHz

　　5 μs analog-to-analog latency

　　4 single-ended analog inputs, configurable as microphone or line inputs

　　Dual stereo digital microphone inputs

　　Stereo analog audio output, single-ended or differential, configurable as either line output or headphone driver

　　PLL supporting any input clock rate from 8 MHz to 27 MHz

　　Full duplex, asynchronous sample rate converters (ASRCs)

　　Power supplies

　　Analog and digital input/output of 1.8 V to 3.3 V

　　Digital signal processing (DSP) core of 1.1 V to 1.8 V

　　Low power

　　I2C and SPI control interfaces, self boot from I2C EEPROM

　　7 multipurpose (MPx) pins for digital controls and outputs

　　ADAU1777应用:

　　Noise canceling handsets, headsets, and headphones

　　Bluetooth® active noise canceling (ANC) handsets, headsets, and headphones

　　Personal navigation devices

　　Digital still and video cameras

　　图1. ADAU1777功能框图

　　评估板EVAL-ADAU1777Z

　　This user guide explains the design and setup of the EVAL-ADAU1777Z evaluation board.

　　This evaluation board provides full access to all analog and digital inputs/outputs on the ADAU1777. The ADAU1777 core is controlled by Analog Devices, Inc., SigmaStudio™ software, which interfaces to the board via a USB connection. The EVAL-ADAU1777Z can be powered by a single AAA battery, by the USB bus, or by a single 3.8 V to 5.5 V supply; any of these supplies are regulated to the voltages required on the board. The printed circuit board (PCB) is a 4-layer design, with a single ground plane and a single power plane on the inner layers. The board contains connectors for external microphones and speakers. The master clock can be provided externally or by the on-board 12.288 MHz passive crystal.

　　评估板EVAL-ADAU1777Z包括:

　　EVAL-ADAU1777Z evaluation board

　　EVAL-ADUSB2EBZ (USBi) communications adapter

　　USB cable with mini-B plug

　　Evaluation board/software quick start guide

　　图2. 评估板EVAL-ADAU1777Z外形图

　　图3. 评估板EVAL-ADAU1777Z框图

　　评估板EVAL-ADAU1777Z材料清单:

　　详情请见:

ADAU1777.pdf

EVAL-ADAU1777Z-UG-1055.pdf