AKM AK4957 24位立体声CODEC解决方案

AKM公司的AK4957是集成了麦克风,扬声器,视频放大器和LDO的24位立体声CODEC,具有录音功能,播放功能和视频功能,主时钟有PLL和外接时钟两种模式,MIC放大器具有+21dB/+18dB/+16dB/+14dB/+8dB/0dB增益,数字自动音量控制(ALC),模拟电源(AVDD)2.8V-3.6V,数字电源(DVDD)1.6V-2.0V,适合于具有录音/播放功能的手提设备.本文介绍了AK4957主要特性,框图, 立体声和单声道数字MIC连接图,以及评估板AKD4957-B功能,框图,电路图和PCB布局图.

The AK4957 is a 24bit stereo CODEC with a microphone, speaker, video amplifiers and LDO. The input circuits include a microphone amplifier and the output circuits include a speaker amplifier. It is suitable for portable application with recording/playback function. A one channel composite In/Out video amplifier is also integrated. The AK4957 is available in a small 32pin QFN (4mm x 4mm, 0.4mm pitch), saving mounting area on the board.

AK4957主要特性:

1. Recording Functions

• Stereo Single-ended input with two Selectors

• MIC Amplifier (+21dB/+18dB/+16dB/+14dB/+8dB/0dB)

• Digital ALC (Automatic Level Control) (Setting Range: +36dB ∼ −54dB, 0.375dB Step)

• ADC Performance: S/(N+D): 83dB, DR, S/N: 88dB (MIC-Amp=+18dB)S/(N+D): 85dB, DR, S/N: 96dB (MIC-Amp=0dB)

• Microphone Sensitivity Compensation

• 5 Band Notch Filter..

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