關鍵詞： D類放大器 , MAX98400 , Maxim , MP3 , 塢站

Maxim公司的MAX98400A/MAX98400B是高性能熱效率高的D類音頻放大器, MAX98400A能向8歐姆負載提供2x20W或向4歐姆負載提供1x40W, MAX98400B則向8歐姆負載提供2x8W功率.單電源8V 到28V工作,提供67dB PSRR,12V時的效率高達90%,主要用在LCD/PDP TV,LCD監視器,MP3塢站和筆記本PC.本文介紹了MAX98400A/MAX98400B主要特性, MAX98400A/B功能方框圖,以及MAX98400A立體聲和單聲道配置圖, MAX98400 D類音頻放大器參考設計主要特性,電路圖,材料清單和PCB布局圖.

The MAX98400A/MAX98400B Class D amplifiers provide high-performance, thermally efficient amplifier solutions. The MAX98400A delivers 2x20W into 8I loads or 1x40W into a 4I load. The MAX98400B delivers 2x12W into 8I loads.

An integrated limiting circuit prevents output clipping distortion, protects small speakers from transient voltages, and reduces power dissipation.

A thermal-foldback feature can be enabled to automatically reduce the output power at above a junction temperature of +120NC. Traditional thermal protection is also available in addition to robust overcurrent protection.

The ICs operate from a single 8V to 28V supply and provide a high 67dB PSRR, eliminating the need for a regulated power supply. They offer up to 90% efficiency from a 12V supply.

Filterless modulation allows the ICs to pass EN55022B EMI limits with 1m cables using only a low-cost ferrite bead and small-value capacitor on each output. Both devices feature eight digitally controlled gain settings.

Comprehensive click-and-pop reduction circuitry minimizes noise coming into and out of shutdown.

The MAX98400A/MAX98400B are available in 36-pin and 24-pin TQFN packages, respectively, and are specified over the -40NC to +85NC temperature range.

MAX98400A/MAX98400B主要特性:

Wide 8V to 28V Supply Voltage Range

Single-Supply Operation

Low EMI: Active Emissions Limiting

Clipping Limiter

Low Quiescent Current

Thermal Foldback

Thermal and Overcurrent Protection

MAX98400A/MAX98400B應用:

LCD/PDP Televisions

LCD Monitors

MP3 Docking Stations

Notebook PCs

2011-11-14 13:19:07 上傳

下載附件 (15.88 KB)

圖1.MAX98400A功能方框圖

2011-11-14 13:19:07 上傳

下載附件 (15.2 KB)

圖2.MAX98400B功能方框圖

2011-11-14 13:19:07 上傳

下載附件 (27.06 KB)

圖3.MAX98400A立體聲配置圖

2011-11-14 13:19:07 上傳

下載附件 (20.62 KB)

圖4.MAX98400A單聲道配置圖

MAX98400 D類音頻放大器參考設計

This reference design demonstrates the use of the MAX98400 Class D audio amplifier in a stereo audio docking station application. The MAX98400 2.1 demo box is a complete powered speaker dock that uses two MAX98400 ICs to drive a 3-channel speaker system consisting of two 2in satellite speakers and one 5in subwoofer. The reference design is intended to be used with a portable audio player as its main music source. The overall solution size is very compact and features active equalization, powersupply monitoring, and dynamic equalization for the subwoofer.

2011-11-14 13:19:07 上傳

下載附件 (79.96 KB)