usb一线通音响方案ic
特点：
·兼容usb1.1和usb2.0 full speed
·内建高效率、高性能d类立体声音频放大器
·支持的i2s输入和i2s输出接口模式。取样频率（fs）：48khz
·+6 db增强（剧院模式）
·同时支持总线供电和自供电操作
·支持win me / 2000/xp/vista/win 7和mac os操作系统
·真正的即插即用，无需驱动程序的usb音箱方案
·支持音量/静音控制与外部按钮
·内建5v转3.3v稳压模块
·总效率：80％8ω负载下- 1db，1khz正弦波输入
·音箱psnr值和重低音dr值分别达到80db(psnr)和78db(dr)，采用磁珠滤波可达82db(psnr)，采用时钟滤波可达78db(dr)。
·反流行设计
·过热保护
·低电压关断
·短路侦测
·12 mhz晶振输入
·32引脚lqfp封装（无铅）
综述：
ad62550a是拥有usb/i2s接口的d类单芯片音频功率放大器。当使用usb端口电源，ad62550a可以驱动高达1w的喇叭，是高效率，高性能的d类功率放大器。它还具有一对i2s输入端口和i2s输出端口，i2s输入端口允许外部音源共享d类放大器和喇叭。i2s的输出端口允许接其它高性能音频ic（如ad8356a/ad8256a），并由ad62550a控制。
features
·compliant with usb specification v1.1, and usb2.0 full speed
·embedded high efficiency, high performance classd stereo amplifier
·support i2s input and i2s output interface of master mode
sampling frequencies(fs)：48khz
·+6db enhancement(theater function)
·support both bus-powered and self-powered operation
·supports win me//2000/xp/vista/win 7 and macos
·true plug-and-play application, no driver is required for basic usb speaker application
·support volume/mute control with external button
·built-in 5v to 3.3v regulator for internal device operation
·total efficiency
80% for 8? load @ -1db 1khz sine wave input
·loudspeaker psnr & dr (a-weighting) 80db (psnr), 78db (dr) with bead filter 82db (psnr), 78db (dr) with chock filter
·anti-pop design
·over-temperature protection
·under-voltage shutdown
·short-circuit detection
·12 mhz crystal input
·32-pin lqfp(pb free)
description
ad62550a is a single chip of class-d audio amplifier with usb/i2s interface. when using the power supplied from the usb port, ad62550a can drive a pair of up to 1w speakers due to the built-in,high efficiency and high performance class d amplifiers. the device also has an i2s input port and i2s output port. the i2s input port allows other external audio sources to use the class d amplifier to share the speakers. the i2s output port allows other high performance audio device (i.e.ad8356a/ad8256a) to be controlled by ad62550a.