AKM公司的AK4678是24位立体声CODEC,具有内置麦克风放大器,接收放大器,单声道D类扬声器放大器,无电容的G类耳机放大器和线路放大器.除了音频I/F外还有两个PCM I/F.播放功能包括5波段参数EQ和动态范围控制,因此能自动调整合适音量而不失真.本文介绍了AK4678主要特性,模拟和数字方框图,以及评估板 AKD4678-B功能,方框图,电路图和PCB元件布局图.
The AK4678 is a 24bit stereo CODEC with a built-in Microphone-Amplifier, Receiver-Amplifier, Mono Class-D Speaker-Amplifier, Cap-less Class-G Headphone-Amplifier and Line-Amplifier. The AK4678 features dual PCM I/F in addition to audio I/F that allows easy interfacing in mobile phone designs with Bluetooth I/F. The playback features also include 5-band Parametric EQ and Dynamic Range Control, therefore the AK4678 can automatically adjust a comfortable volume without distortion and provides great flexibility. The AK4678 is available in a 49pin CSP, utilizing less board space than competitive offerings.
AK4678主要特性:
1. Recording Function (Stereo CODEC)
• 4 Stereo Input Selectors
• 4 Stereo Inputs (Single-ended) or 3 Mono Input (Full-differential)
• MIC Amplifier: +24dB ~ −6dB, 3dB step
• 2 Output MIC Power Supplies
• Digital ALC (Automatic Level Control): +36dB ~ −54dB, 0.375dB Step, Mute
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