Maxim 公司的MAX9888是采用FlexSound技術的全特性立體聲音頻CODEC,立體聲DAC的DR為100dB(8kHz fS 96kHz),立體聲ADC的DR為91dB(8kHz fS 96kHz),立體聲低EMI D類放大器950mW/每路,集成了DirectDrive耳機放大器和差分接收放大器,其高性能和低功耗適合用在手持設備.本文介紹了MAX9888主要特性,功能方框圖,典型應用電路圖以及MAX9888評估板主要特性,方框圖,電路圖和材料清單. The MAX9888 is a full-featured audio CODEC whose high performance and low power consumption make it ideal for portable applications.

Class D speaker amplifiers provide efficient amplification for two speakers. Low radiated emissions enable completely filterless operation. Integrated bypass switches optionally connect an external amplifier to the transducer when the Class D amplifiers are disabled.

DirectDrive® headphone amplifiers provide a true ground-referenced output, eliminating the need for large DC-blocking capacitors. 1.8V headphone opera-tion ensures low power consumption. The device also includes a differential receiver amplifier.

Three differential analog microphone inputs are available as well as support for two PDM digital microphones. Integrated switches allow microphone signals to be routed out to external devices. Two flexible single-ended or differential line inputs may be connected to an FM radio or other sources.

Integrated FlexSoundK technology improves loud-speaker performance by optimizing the signal level and frequency response while limiting the maximum distor-tion and power at the output to prevent speaker damage. Automatic gain control (AGC) and a noise gate optimize the signal level of microphone input signals to make best use of the ADC dynamic range.

The device is fully specified over the -40NC to +85NC extended temperature range.

MAX9888主要特性:

100dB DR Stereo DAC (8kHz < fS < 96kHz)

91dB DR Stereo ADC (8kHz < fS < 96kHz)

Stereo Low EMI Class D Amplifiers 950mW/Channel (8I, VSPKVDD_ = 4.2V)

Stereo DirectDrive Headphone Amplifiers

Differential Receiver Amplifier

2 Stereo Single-Ended/Mono Differential Line Inputs

3 Differential Microphone Inputs

FlexSound Technology 5-Band Parametric EQ Automatic Level Control (ALC) Excursion Limiter Speaker Power Limiter Speaker Distortion Limiter Microphone Automatic Gain Control and Noise Gate

Dual I2S/PCM/TDM Digital Audio Interfaces

Asynchronous Digital Mixing

Supports Master Clock Frequencies from 10MHz to 60MHz

RF Immune Analog Inputs and Outputs

Extensive Click-and-Pop Reduction Circuitry

I2C Control Interface

63 WLP Package (3.80mm x 3.30mm, 0.4mm Pitch)

圖1.MAX9888功能框圖

圖2.MAX9888典型應用電路圖:采用模擬麥克風輸入和旁路開關

圖3.MAX9888典型應用電路圖:采用數字麥克風輸入和接收放大器

MAX9888評估板

The MAX9888 evaluation kit (EV kit) is a fully assembled and tested circuit board that evaluates the MAX9888 audio codec. The MAX9888 is an integrated audio codec including microphone amplifiers, line amplifiers, an earpiece amplifier, stereo Class D amplifiers, stereo DirectDriveM headphone amplifiers, and digital signal processing. The EV kit also includes Windows XPM-,Windows VistaM-, and WindowsM 7-compatible software that provides a simple graphical user interface (GUI) for exercising the features of the device.

The EV kit provides access to all analog and digital inputs/outputs on the device. To enable easy connection to a wide range of audio sources, audio devices are included to convert both USB data and S/PDIF data to I2S.

The EV kit integrates a MAXQ2000 microcontroller to enable I2C communication with devices on the EV kit.

The EV kit software, running on a Windows PC, communicates with the EV kit over a standard USB port. The EV kit software provides an intuitive interface to exercise the
functions of the device.

The EV kit comes with a MAX9888EWY+ installed.

MAX9888評估板主要特性:

2.8V to 5.5V Single-Supply Operation

Proven Audio PCB Layout

On-Board USB-to-I2C Interface

On-Board USB-to-I2S Converter

On-Board S/PDIF Transceiver

On-Board Clock Source

On-Board Digital Microphone

Evaluates the MAX9888EWY+ in a 3.8mm x

3.3mm, 63-Bump WLP Package

Windows XP-, Windows Vista-, and Windows

7-Compatible Software

Fully Assembled and Tested

圖4.MAX9888評估板方框圖

圖5.MAX9888評估板電路圖(1)

圖6.MAX9888評估板電路圖(2)

圖7.MAX9888評估板電路圖(3)

圖8.MAX9888評估板電路圖(4)

圖9.MAX9888評估板電路圖(5)

MAX9888評估板材料清單(BOM):





圖10.MAX9888評估板元件布局圖
詳情請見:
http://datasheets.maxim-ic.com/en/ds/MAX9888.pdf
和
http://datasheets.maxim-ic.com/en/ds/MAX9888EVKIT.pdf