ADI公司的ADAU1781是低功耗24位立體聲編譯碼器,可編程的SigmaDSP音頻處理核,低噪音DAC和ADC支持取樣速率從8kHz到96kHz,揚聲器能向8歐姆負載輸出400mW,模擬和數字I/O電壓1.8 V- 3.3 V,主要用在數碼相機和數碼攝像機.本文介紹了ADAU1781主要特性,方框圖以及差分輸入系統,模擬麥克風輸入系統, 單端立體聲線輸入框圖和立體聲數字麥克風輸入系統的框圖,評估板EVAL-ADAU1781Z主要特性,框圖,電路圖,材料清單和PCB元件布局圖.

The ADAU1781 is a low power, 24-bit stereo audio codec. The low noise DAC and ADC support sample rates from 8 kHz to 96 kHz. Low current draw and power saving modes make the ADAU1781 ideal for battery-powered audio applications.

A programmable SigmaDSP® core provides enhanced record and playback processing to improve overall audio quality.

The record path includes two digital stereo microphone inputs and an analog stereo input path. The analog inputs can be configured for either a pseudo differential or a single-ended stereo source. A dedicated analog beep input signal can be mixed into any output path. The ADAU1781 includes a stereo line output and speaker driver, which makes the device capable of supporting dynamic speakers.

The serial control bus supports the I2C® or SPI protocols, and the serial audio bus is programmable for I2S, left-justified, right-justified, or TDM mode. A programmable PLL supports flexible clock generation for all standard rates and available master clocks from 11 MHz to 20 MHz

ADAU1781主要特性:

24-bit stereo audio ADC and DAC

400 mW speaker amplifier (into 8 Ω load)

Programmable SigmaDSP audio processing core

Wind noise detection and filtering

Enhanced stereo capture (ESC)

Dynamics processing

Equalization and filtering

Volume control and mute

Sampling rates from 8 kHz to 96 kHz

Stereo pseudo differential microphone input

Optional stereo digital microphone input pulse-density modulation (PDM)

Stereo line output

PLL supporting a range of input clock rates

Analog and digital I/O 1.8 V to 3.3 V

Software control via SigmaStudio graphical user interface

Software-controllable, clickless mute

Software register and hardware pin standby mode

32-lead, 5 mm × 5 mm LFCSP

ADAU1781應用:

Digital still cameras

Digital video cameras

圖1. ADAU1781框圖

圖2. ADAU1781差分輸入系統框圖

圖3. ADAU1781模擬麥克風輸入系統框圖

圖4. ADAU1781單端立體聲線輸入系統框圖

圖5. ADAU1781立體聲數字麥克風輸入系統框圖

ADAU1781 SigmaDSP評估板EVAL-ADAU1781Z
 
This user guide explains the design and setup of the ADAU1781 SigmaDSP® evaluation board.

This evaluation board provides full access to all analog and digital I/Os on the ADAU1781. The SigmaDSP is controlled by Analog Devices, Inc., SigmaStudio™ software, which interfaces to the board via a USB connection. This evaluation board can be powered either over the USB bus or by a single 3.8 V to 6 V supply, which is regulated to the voltages required on the board. The PC board is a 4-layer design, with a single ground plane and a single power plane on the inner layers. The board contains on-board microphones and speaker, and connectors for external microphones and speaker. The master clock can be provided externally or by the on-board 12.288 MHz active oscillator.

EVAL-ADAU1781Z評估包包括:

ADAU1781 evaluation board

EVAL-ADUSB2EBZ (USBi) communications adapter

USB cable with Mini-B plug

Evaluation board/software quick-start guide

 
圖6.評估板EVAL-ADAU1781Z外形圖
 
圖7.評估板EVAL-ADAU1781Z功能框圖

圖8.評估板EVAL-ADAU1781Z電路圖: SigmaDSP,模擬I/O和主時鐘發生

圖9.評估板EVAL-ADAU1781Z電路圖:數字麥克風接口

圖10.評估板EVAL-ADAU1781Z電路圖:串行音頻數據接口

圖11.評估板EVAL-ADAU1781Z電路圖:電源

圖12.評估板EVAL-ADAU1781Z電路圖:GPIO

圖13.評估板EVAL-ADAU1781Z電路圖:通信接口

評估板EVAL-ADAU1781Z材料清單:




圖14.評估板EVAL-ADAU1781Z PCB元件布局圖
詳情請見:
http://www.analog.com/static/imported-files/data_sheets/ADAU1781.pdf
和
http://www.analog.com/static/imported-files/user_guides/UG-177.pdf