The MAX98357A/MAX98357B are digital pulse-code mod­ulation (PCM) input Class D power amplifiers that provide Class AB audio performance with Class D efficiency. These ICs offer five selectable gain settings (3dB, 6dB, 9dB, 12dB, and 15dB) in I2S/left-justified mode set by a single gain select input and a fixed 12dB gain in TDM mode.

　　The digital audio interface is highly flexible with the MAX98357A supporting I2S data and the MAX98357B supporting left-justified data. Both ICs support 8 channel time division multiplexed (TDM) data. The digital audio interface accepts specified sample rates between 8kHz and 96kHz for all supported data formats. The ICs can be configured to produce a left channel, right channel, or (left/2 + right/2) output from the stereo input data. The ICs operate using 16/24/32-bit data for I2S and left-justified modes as well as 16-bit or 32-bit data using TDM mode. The ICs eliminate the need for the external MCLK signal that is typically used for PCM communication. This reduc­es EMI and possible board coupling issues in addition to reducing the size and pin count of the ICs.

　　The ICs also feature a very high wideband jitter toler­ance (12ns typ) on BCLK and LRCLK to provide robust operation.Active emissions-limiting, edge-rate limiting, and over­shoot control circuitry greatly reduce EMI. A filterless spread-spectrum modulation scheme eliminates the need for output filtering found in traditional Class D devices and reduces the component count of the solution.

　　The ICs are available in 9-pin WLP (1.345mm x 1.435mm x 0.64mm) and 16-pin TQFN (3mm x 3mm x 0.75mm) packages and are specified over the -40 ℃ to +85℃ tem­perature range.

　　MAX98357A/MAX98357B主要特性:

　　Single-Supply Operation (2.5V to 5.5V)

　　3.2W Output Power into 4Ω at 5V

　　2.4mA Quiescent Current

　　92% Efficiency (RL = 8Ω, POUT = 1W)

　　25μVRMS Output Noise (AV = 15dB)

　　Low 0.015% THD+N at 1kHz

　　No MCLK Required

　　Sample Rates of 8kHz to 96kHz

　　Supports Left, Right, or (Left/2 + Right/2) Output

　　Sophisticated Edge Rate Control Enables Filterless Class D Outputs

　　77dB PSRR at 1kHz

　　Low RF Susceptibility Rejects TDMA Noise from GSM Radios

　　Extensive Click-and-Pop Reduction Circuitry

　　Robust Short-Circuit and Thermal Protection

　　Available in Space-Saving Packages: 1.345mm x 1.435mm WLP (0.4mm Pitch) and 3mm x 3mm TQFN

　　MAX98357A/MAX98357B应用:

　　Notebook and Netbook Computers

　　Cellular Phones

　　Tablets

　　图1.MAX98357A/MAX98357B功能框图

　　图2.MAX98357A/MAX98357B增益6dB左路PCM工作电路

　　图3.MAX98357A/MAX98357B增益12dB左路PCM工作电路

　　图4.MAX98357A/MAX98357B增益6dB右路PCM工作电路

　　图5.MAX98357A/MAX98357B增益6dB(左路/2+右路/2)PCM工作电路

　　图6.MAX98357A/MAX98357B采用两个IC的立体声PCM工作电路

　　图7.MAX98357A/MAX98357B增益12dB通路TDM工作电路

　　MAX98357开发板DEV(WLP)

　　The MAX98357 development board (DEV board) is a fullyassembled and tested PCB that evaluates the MAX98357I2S digital input Class D power amplifier. The DEV boardoperates from a single 2.5V to 5.5V DC power supply andis capable of delivering 3.2W into a 4Ω load. The deviceoutputs can be connected directly to a speaker load forfilterless applications. However, a filter can be added toease evaluation. The MAX98357A accepts standard I2Sdata and the MAX98357B accepts left-justified digital audio data. Both versions also support 8-channel TDMaudio data.

　　The MAX98357 evaluation system (EV system) includesthe MAX98357 DEV board and Maxim Integrated’s audiointerface board (AUDINT001 board).

　　The AUDINT001 board provides an easy-to-use USBaudio-to-I2S converter. This allows for any computer tobecome a digital audio source, which can be used toevaluate the devices. The AUDINT001 board can also beused to power the MAX98357. This allows for a completeevaluation from a single USB connection.

　　MAX98357开发板DEV(WLP)主要特性:

　　●● 2.5V to 5.5V Single-Supply Operation

　　●● Only a Single External Component (VDD Capacitor)Required in Many Applications

　　●● I2S, Left-Justified, or TDM Input

　　●● Five Selectable Gains (3db, 6dB, 9dB, 12dB, and15dB)

　　●● Audio Channel Select (Left, Right, and Mono Mix)

　　●● Filterless Operation

　　●● Optional Class D Output Filters for Ease ofEvaluation

　　●● Proven PCB Layout

　　●● Fully Assembled and Tested

　　图8.MAX98357开发板DEV(WLP)简化框图

　　图9.MAX98357开发板DEV(WLP)电路图

　　MAX98357开发板DEV(WLP)材料清单:

　　图10.MAX98357开发板DEV(WLP) PCB设计图(1)

　　图11.MAX98357开发板DEV(WLP) PCB设计图(2)

　　图12.MAX98357开发板DEV(WLP) PCB设计图(3)

　　图13.MAX98357开发板DEV(WLP) PCB设计图(4)

　　图14.MAX98357开发板DEV(WLP) PCB设计图(5)

　　MAXIM是美信公司(Maxim Integrated Products)的英文缩写，全球最好的模拟信号和混合信号半导体公司。同时MAXIM也是一款时尚潮流杂志的名字，maxim内容涵盖了音乐、体育、电视、电影、潮流名人等。也是比较温和的男性杂志，以更多的消遣内容为主。

　　2001年，Maxim并购了著名的Dallas Semiconductor。是全球最好的模拟信号和混合信号半导体公司.

　　它们的使命是不断创造高品质的模拟工程解决方案，在世界范围内为基于微处理器的电子产品客户提供增值服务。它们通过努力达到它们的成本与业绩Maxim Integrated Products成立于1983年，总部位于美国加利福尼亚的Sunnyvale，公司拥有9300多名员工，是世界范围内模拟和混合信号集成产品的设计、开发与生产领域的领导者之一。通过对温度、压力、声音等现实世界的各种信号进行检测、放大，并将其转换成计算机处理所需要的数字信号, Maxim的电路把现实世界与数字世界“连接”在一起。

　　目标、缩短新品上市时间并不断提高它们的生产能力，坚持不懈地为它们的客户和公司股权持有者提供最好的服务。

　　任何电子产品的核心都是一个数字核，它与人类、真实的物理世界、供电电源及其它数字系统相关联。Maxim是全球模拟、混合信号、高频及数字电路设计、研发、制造的领导者，所提供的产品能够实现上述数字内核与周边系统的连接。它们在世界范围内拥有大约35,000个大型客户。

　　详情请见:

MAX98357DEV_WLP-MAX98357EVSYS_WLP.pdf

MAX98357A-MAX98357B.pdf