Maxim公司的MAX9879是高效率立體聲D類音頻功率放大器,并集成了立體聲無電容DirectDrive耳機放大器,以D類的效率提供AB類的性能.MAX9879能從3.7V電源向8歐姆負載提供高達715mW的功率,效率88%.D類放大器在1kHz時的THD+N低于0.04%,耳機放大器的THD+N低于0.018%,主要應用在手機和手提媒體播放器.本文介紹了MAX9879的主要特性,簡化方框圖,立體聲模式和單聲道模式的信號通路以及典型應用電路.此外還介紹了MAX9879評估板的主要特性,詳細電
Maxim 公司的MAX9879是高效率立體聲D類音頻
功率放大器,并集成了立體聲無
電容DirectDrive耳機放大器,以D類的效率提供AB類的性能. MAX9879能從3.7V
電源向8歐姆負載提供高達715mW的功率,效率88%.D類放大器在1kHz時的
THD+N低于0.04%,耳機放大器的THD+N低于0.018%,主要應用在
手機和手提媒體播放器.本文介紹了MAX9879的主要特性,簡化方框圖, 立體聲模式和單聲道模式的信號通路以及典型應用電路.此外還介紹了MAX9879評估板的主要特性,詳細電路圖和所用元件列表.
The MAX9879 combines a high-efficiency stereo Cl
ass D audio power amplifier with a stereo capacitor-less DirectDrive&
reg; headph
one amplifier. Maxim’s filterless class D amplifiers with active emissions limiting technology provide Class AB pe
rformance with Class D efficiency.
The Class D power amplifier delivers up to 715mW from a 3.7V supply into an 8ohm ?load with 88% efficiency to extend battery life. The filterless modulation scheme combined with active emission limiting circuitry and spread-spectrum modulation greatly reduces EMI while elim
inating the need for output filtering used in traditional Class D devices.
The headphone amplifier delivers up to 58mW from a 3.7V supply into a
16ohm ?load. Maxim’s patented DirectDrive architecture produces a ground-referenced output from a single supply, eliminating the need for large DC-blocking capacitors, saving cost, space and component height.
The device utilizes a user-defined input architecture, three preamplifier gain settings, an input mixer, volume control, comprehensive click-and-pop suppression, and I2C control. A bypass mode feature disables the integrated Class D amplifier and utilizes an internal DPST switch to allow an external amplifier to drive the speaker that is connected at the outputs of the MAX9879.
The MAX9879 is available in a thermally efficient, space-saving 30-bump UCSP™ package.
MAX9879主要特性:
♦ Better than 9
dBMargin Under EN 55022 Class B Limits with No Filter Components
