原标题：Maxim MAX98358数字PDM输入D类放大器解决方案

　　Maxim公司的MAX98358是脉冲密度调制(PDM)数字输入D类放大器,提供AB类音频性能和D类效率,可选择增益设定(3dB, 6dB, 9dB, 12dB和15dB),单电源2.5V- 5.5V,5V时4Ω输出功率3.2W,效率92%(RL = 8Ω, POUT = 1.5W),1kHz时的THD+N为0.015%,增益为6dB时的输出噪音29μVRMS,主要用在笔记本电脑,手机,平板电脑和手持媒体播放器(PMP).本文介绍了MAX98358主要特性和简化框图,立体声工作电路图以及音频接口板AUDINT1主要特性,简化EV系统框图,电路图,材料清单和PCB设计图.

　　The MAX98358 is a digital pulse-density modulated (PDM) input Class D power amplifier that provides Class AB audio performance with Class D efficiency. This IC offers five selectable gain settings (3dB, 6dB, 9dB, 12dB, and 15dB) set by a single gain-select input (GAIN). The IC can be configured to produce a left channel, right channel, or (left/2 + right/2) output from the stereo input data.

　　The MAX98358 takes a stereo pulse density modulated (SPDM) input signal directly into the DAC. Data on the rising edge of PDM_CLK is considered left-channel data while data on the falling PDM_CLK edge is right channel. A mono sum feature is also implemented with SPDM data input by summing the data from both rising and falling clock edges.

　　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 IC is 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 is specified over the -40°C to +85°C tem­perature range.

　　MAX98358主要特性:

　　Single-Supply Operation (2.5V to 5.5V)

　　3.2W Output Power into 4Ω at 5V

　　1.8mA Quiescent Current (VDD = 3.7V)

　　92% Efficiency (RL = 8Ω, POUT = 1.5W)

　　29μVRMS Output Noise (AV = 6dB)

　　Low 0.015% THD+N at 1kHz

　　Supported PDM_CLK Rates of 1.84MHz–4.32MHz and 5.28MHz–8.64MHz

　　Supports Left, Right, or Left/2 + Right/2 Outputs

　　Sophisticated Edge Rate Control Enables Filterless Class D Outputs

　　77dB PSRR at 217Hz

　　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) 3mm x 3mm TQFN

　　MAX98358应用:

　　Notebook and Netbook Computers

　　Cellular Phones

　　Tablets

　　Portable Media Players

　　图1.MAX98358简化框图

　　图2.MAX98358立体声工作电路图

　　音频接口板AUDINT1

　　The Maxim Audio Interface 1 (AUDINT1) board providesboth an I2C and I2S interface to facilitate the evaluationof compatible Maxim Development (DEV) boards. MaximDEV boards that are evaluated with the AUDINT1 interfaceboard can require custom GUI software, which is availableas a download from Maxim’s evkit-software web page.

　　The AUDINT1 board and a compatible DEV board areordered together as an evaluation system (EV system).

　　Ordering information for EV systems is located in the EVsystem data sheet.

　　Refer to the appropriate EV system data sheet for quickstart and detailed operating instructions.

　　The AUDINT1 board is provided as part of selected Maximevaluation systems (EV system) to evaluate Maxim partsonly. The use of the AUDINT1 board as a development target is not supported. Refer to the MAXQ2000 evaluationkit data sheet for this purpose.

　　音频接口板AUDINT1优势和特性:

　　●● USB Powered (+5V)

　　●● USB-to-I2C (USB CONTROL)

　　●● USB-to-I2S (USB AUDIO)

　　●● On-Board Master Clock Sources

　　●● On-Board LDOs (+1.2V, +1.8V, +3.3V)

　　●● Compatible with Standard FTDI VCP Drivers

　　●● Fully Assembled and Tested

　　音频接口板AUDINT1材料清单:

　　详情请见:

MAXAUDINT001.pdf

MAX98358.pdf