AKM AK4954A低功耗32位CODEC解决方案

AKM公司的AK4954A是集成了麦克风,耳机放大器和扬声器放大器的低功耗32位CODEC,输入电路包括麦克风放大器和自动电平控制(ALC)电路,输出电路包括无电容的耳机放大器和扬声器放大器,非常适合于手提音频应用.本文介绍了AK4954A 主要特性,框图,以及评估板AK4954A方框图和电路图.
The AK4954A is a low power consumption 32-bit stereo CODEC with a microphone, a headphone and a speaker amplifiers. The input circuits include a microphone amplifier and an ALC (Automatic Level Control) circuit, and the output circuits include a cap-less headphone amplifier and a speaker amplifier. It is suitable for portable application with recording/playback function. The integrated charge pump circuit generates a negative voltage and removes the output AC coupling capacitors. The speaker amplifier has a wide operating voltage range, which is from 0.9V to 5.5V, enabling a direct drive to batteries. The AK4954A is available in a small 32-pin QFN (4x4mm 0.4mm pitch), utilizing less board space than competitive offerings.
AK4954A 主要特性:
1. Recording Function
• Two Low Noise Microphone Power Supplies
• Stereo Single-ended input with three Selectors
• Low Noise Microphone Amplifier (+26dB/+20dB/+13dB/+6dB/0dB)
• Digital ALC (Automatic Level Control)
(Setting Range: +36dB ∼ −52.5dB, 0.375dB Step)
• ADC Performance: S/(N+D): 88dB, DR, S/N: 97dB (Microphone Amplifier =+20dB)
S/(N+D): 88dB, DR, S/N: 100dB (Microphone Amplifier =0dB)
• Two Types of Decimation Filters
• Overflow Detection
• Wind-noise Reduction Filter
• Stereo Separation Emphasis Circuit
• 5-band Notch Filter
• Digital Microphone Interface
2. Playback Function
• Digital ALC (Automatic Level Control) (Setting Range: +36dB ~ −52.5dB, 0.375dB Step)
• 3-band Dynamic Range Control Circuit
• Digital Volume Control (+6dB ~ −65.5dB, 0.5dB Step, Mute)
• Capacitor-less Stereo Headphone Am...