ADI公司的ADAU1401是集成了兩個(gè)ADC和四個(gè)DAC以及微控制器類(lèi)的控制接口的SigmaDSP 28/56位音頻數字信號處理器(DSP),信號處理包括均衡,音頻混合,低音增強,多帶動(dòng)態(tài)處理,延遲補償,揚聲器補償以及立體聲圖像加寬等,可以彌補真實(shí)揚聲器,放大器的不足,從而改善聽(tīng)覺(jué)環(huán)境,提高音頻質(zhì)量.主要用在多媒體揚聲器系統,MP3播放器揚聲器,汽車(chē)音響,微型立體聲,數字電視,音樂(lè )樂(lè )器等.本文介紹了ADAU1401主要特性, 功能方框圖, 系統框圖, 自舉模式, I2C與SPI控制和電路圖,以及評估板EVAL-ADAU1401AEBZ主要特性,框圖,電路圖和PCB元件布局圖.
The ADAU1401 is a complete single-chip audio system with a 28-/56-bit audio DSP, ADCs, DACs, and microcontroller-like control interfaces. Signal processing includes equalization, cross over, bass enhancement, multiband dynamics processing, delay compensation, speaker compensation, and stereo image widening. This processing can be used to compensate for real-world limitations of speakers, amplifiers, and listening environments, providing dramatic improvements in perceived audio quality.
Its signal processing is comparable to that found in high end studio equipment. Most processing is done in full 56-bit, double precision mode, resulting in very good low level signal performance. The ADAU1401 is a fully programmable DSP. The easy to use SigmaStudio™ software allows the user to graphically configure a custom signal processing flow using blocks such as biquad filters, dynamics processors, level controls, and GPIO interface controls.
ADAU1401 programs can be loaded on power-up either from a serial EEPROM through its own self-boot mechanism or from an external microcontroller. On power-down, the current state of the parameters can be written back to the EEPROM from the ADAU1401 to be recalled the next time the program is run.
Two Σ-Δ ADCs and four Σ-Δ DACs provide a 98.5 dB analog input to analog output dynamic. Each ADC has a THD + N of −83 dB, and each DAC has a THD + N of −90 dB. Digital input and output ports allow a glueless connection to additional ADCs and DACs. The ADAU1401 communicates through an I2C® bus or a 4-wire SPI port.

ADAU1401主要特性:
28-/56-bit, 50 MIPS digital audio processor
2 ADCs: SNR of 100 dB, THD + N of −83 dB
4 DACs: SNR of 104 dB, THD + N of −90 dB
Complete standalone operation
Self-boot from serial EEPROM
Auxiliary ADC with 4-input mux for analog control
GPIOs for digital controls and outputs
Fully programmable with SigmaStudio graphical tool
28-bit × 28-bit multiplier with 56-bit accumulator for full double-precision processing
Clock oscillator for generating master clock from crystal
PLL for generating master clock from 64 × fS, 256 × fS, 384 × fS, or 512 × fS clocks
Flexible serial data input/output ports with I2S-compatible, left-justified, right-justified, and TDM modes
Sampling rates of up to 192 kHz supported
On-chip voltage regulator for compatibility with 3.3 V systems
48-lead, plastic LQFP

ADAU1401應用:
Multimedia speaker systems
MP3 player speaker docks
Automotive head units
Minicomponent stereos
Digital televisions
Studio monitors
Speaker crossovers
Musical instrument effects processors
In-seat sound systems (aircraft/motor coaches)

圖1.ADAU1401功能方框圖

圖2.ADAU1401系統框圖

圖3.ADAU1401自舉模式電路圖

圖4.ADAU1401 I2C控制電路圖

圖5.ADAU1401 SPI控制電路圖

評估板EVAL-ADAU1401AEBZ
The EVAL-ADAU1401AEBZ is a platform that operates all of the ADAU1401A’s functions with a full range of analog and digital inputs and outputs. Digital I/O connections are available in both S/PDIF and 3-wire serial data formats. The DSP is controlled by the SigmaStudio™ software, which interfaces to the board through a USB connection. This evaluation board is powered by a single supply, which is regulated to the proper voltages on the board. The PCB is in a 6” × 6” 4-layer design, with a single ground plane and a single power plane on the inner layers.
The ADAU1401A can be controlled via the USBi interface control board connected to the I2C/SPI communications interface. On-board self-boot EEPROM is included for operating the board independently of the SigmaStudio software. Push-buttons, LEDs, potentiometers, and other interface options on the included GPIO board can be connected to the evaluation board to enable GPIO control.
The EVAL-ADAU1401AEBZ can also be used for evaluation of the pin-compatible ADAU1701 and ADAU1702 SigmaDSP®s. The differences between the ADAU1401A, ADAU1401, ADAU1701, and ADAU1702 are:
• The ADAU1701, ADAU1401A, and ADAU1401 have 1024 program RAM locations, while the ADAU1702 has 512 program RAM locations.
• The ADAU1701 has 2k words of data memory, while the ADAU1702 has 0.5k words of data memory.

評估包包括:
EVAL-ADAU1401AEBZ evaluation board
GPIO control board
USBi board
Universal power supply
Mini-USB cable
Evaluation board/software quick-start guide, including a download link for the SigmaStudio tools
ADAU1401A, ADAU1401, ADAU1701, and ADAU1702 SigmaDSP Evaluation Board
Full-Featured ADAU1401 SigmaDSP evaluation board that operates all of the ADAU1401/ADAU1701/ADAU1702’s functions with a full range of analog and digital inputs and outputs as well as a self-boot EEPROM.USBi, 6 V power supply and an attachable GPIO control board are included in the package.

圖6.評估板EVAL-ADAU1401AEBZ外形圖

圖7.評估板EVAL-ADAU1401AEBZ框圖

圖8.評估板EVAL-ADAU1401AEBZ電路圖

圖9.評估板EVAL-ADAU1401AEBZ電路圖:CPLD

圖10.評估板EVAL-ADAU1401AEBZ電路圖:模擬輸入和輸出濾波器

圖11.評估板EVAL-ADAU1401AEBZ電路圖:S/PDIF接收器和發(fā)送器

圖12.評估板EVAL-ADAU1401AEBZ復位和USB電路圖

圖13.評估板EVAL-ADAU1401AEBZ電路圖:多用圖引腳接口

圖13.評估板EVAL-ADAU1401AEBZ電路圖:電源

圖14.評估板EVAL-ADAU1401AEBZ電路圖:GPIO板連接器

圖15.評估板EVAL-ADAU1401AEBZ電路圖:GPIO板控制

圖16.評估板EVAL-ADAU1401AEBZ PCB元件布局圖:頂層