ADI公司的ADAU1373是低功耗立體聲CODEC,集成了數字音頻處理,支持立體聲48kHz錄音和播放,立體聲ADC和DAC支持取樣速率從8kHz到48kHz以及數字音量控制,帶PGA的八個單端或四個差分輸入提供增益從-12dB到+18dB.48kHz和1.8V錄音功耗7mW,播放功耗6mW,主要用在手機,平板電腦,電子書,手持媒體播放器.本文介紹了ADAU1373主要特性,方框圖, 立體聲D類應用電路圖以及ADAU1373評估板電路圖,材料清單和PCB元件布局圖.

The ADAU1373 is a low power, stereo audio codec with integrated digital audio processing that supports stereo 48 kHz record and playback. The stereo audio ADCs and DACs support sampling rates from 8 kHz to 48 kHz, as well as a digital volume control.

Eight single-ended or four differential analog inputs with PGAs are provided for adjusting the gain from −12 dB to +18 dB. They can be configured for microphones or line level signals.

Two stereo digital microphone inputs are supported; four digital microphones can be connected in total. In addition, three serial digital audio input/output ports are provided with asynchronous sample rate converters (ASRCs) to support various sampling rates, allowing for flexible system design in mobile phone applications. The inputs can be mixed and selected before the ADC or con-figured to bypass the ADC. Two stereo DACs are included, with a flexible mixing option for routing the signals internally.

The analog output side consists of line outputs, headphone output, speaker output, and receiver output. Two stereo single-ended line level outputs, which can be configured as two differential outputs, are included. The headphone output is stereo true ground centered (eliminating the need for coupling capacitors), with efficient Class-G (rail switching) architecture. The efficient stereo filterless Class-D switching amplifier provides ~1 W of stereo power for speakers. The differential receiver amplifier can be used to connect the separate receiver speaker. Two PLL blocks, which can lock to the inputs from 8 kHz to 27 MHz, are included.

The DSP allows system designers to compensate for the real-world limitations of microphones, speakers, amplifiers, and listening environments, resulting in a dramatic improvement in perceived audio quality through equalization, multiband compression, and limiting algorithms. The SigmaStudio™ graphical development tool, which includes audio processing blocks such as filters, mixers, dynamics processors, and amplifiers for fast development of custom signal flows, is used to program the ADAU1373.

ADAU1373主要特性:

1 stereo ADC and 2 stereo DACs with sampling rates from 8 kHz to 48 kHz

Low power: 7 mW record, 6 mW playback, 48 kHz at 1.8 V

8 single-ended or 4 differential inputs with PGA

2 microphone bias reference voltages with current sense

2 stereo digital microphone inputs

Flexible analog input/output mixers

1 stereo differential or 2 stereo single-ended line outputs

True ground-centered stereo Class-G headphone amplifier, capable of 2 × 50 mW into 16 Ω at 1.8 V, 10% THD

Filterless stereo Class-D speaker amplifier, capable of 2 × 880 mW into 8 Ω at 3.6 V, 10% THD

Differential earpiece amplifier capable of driving 32 Ω

2 PLLs, supporting input clocks from 8 kHz to 27 MHz

I2C control interface

Digital audio processing

3 digital audio input and output ports with ASRC

I2S, PCM, right-justified, left-justified modes

4.05 mm × 3.82 mm, 81-ball, 0.4 mm pitch WLCSP package

−40℃ to +85℃ operating temperature range

ADAU1373應用:

Mobile phones, tablet PCs, e-books, portable media players

圖1. ADAU1373功能方框圖

圖2. ADAU1373典型立體聲D類應用電路圖

ADAU1373評估板

The ADAU1373 is a low power audio codec that supports stereo record and playback. It provides eight single-ended or four differential analog inputs with PGA for adjusting the gain. The support for two stereo digital microphone inputs is provided so that, in total, four digital microphones can be connected. In addition, three serial digital audio in/out ports are provided with ASRCs to support various sampling rates at the input/output ports, allowing flexible system design.

The analog output side consists of line outputs, a headphone output, a speaker output, and a receiver output. The two stereo single-ended line level outputs are included, which can be configured as two differential outputs. The headphone output is stereo true-ground-centered with efficient Class-G architecture. The efficient stereo filterless Class-D switching amplifier pro-vides around 1 W stereo power for speakers. The differential receiver amplifier can be used to connect the separate receiver speaker.

The ADAU1373 evaluation board includes the complete application circuit for the ADAU1373. The board is featured with USBi connection to the SigmaStudio™ graphical develop-ment tool running on a host PC, which is used to program the ADAU1373.

Included in this user guide is a detailed description for the ADAU1373 evaluation board. It is recommended that the ADAU1373 data sheet be read along with this user guide. Full details about the part are available in the ADAU1373 data sheet, which provides more detailed information about the specifica-tions, internal block diagrams, and application guidance for the codec IC.

圖3. ADAU1373評估板電路圖(1)

圖4. ADAU1373評估板電路圖(2)

圖5. ADAU1373評估板電路圖(3)

圖6. ADAU1373評估板電路圖(4)

圖7. ADAU1373評估板電路圖(5)

圖8. ADAU1373評估板電路圖(6)

圖9. ADAU1373評估板電路圖(7)

圖10. ADAU1373評估板電路圖(8)

圖11. ADAU1373評估板電路圖(9)
ADAU1373評估板材料清單:



圖12. ADAU1373評估板電源部分

圖13. ADAU1373評估板數字音頻接口和風細雨數字麥克風接口部分
詳情請見:
http://www.analog.com/static/imported-files/data_sheets/ADAU1373.pdf
和
http://www.analog.com/static/imported-files/user_guides/UG-284.pdf