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AKM公司的AK4688是立體聲音頻CODEC,集成了具有24位輸入/輸出數據的ADC和DAC接口,支持異步操作.64x過取樣,取樣速率高達48kHz,線性相位數字抗混淆濾波器,S/(N+D)為83dB,動態范圍105dB,S/N為99dB, 3.3V單電源輸出達2Vrms,適合用于數字錄音系統,DTV,藍光記錄儀和家庭影院.本文介紹了AK4688主要特性,方框圖,典型應用電路以及評估板AKD4688-A主要功能,方框圖,電路圖和PCB元件布局圖. The AK4688 is a stereo audio CODEC. The integrated ADC and DAC interfaces accept up to 24-bit input/output data and support an asynchronous operation. The input range of the pre-amplifier, that supports line inputs, is adjustable by an external resistor. A ground referenced 2Vrms output with a 3.3V single power supply is achieved by an integrated charge pump, reducing external parts such as AC-coupling capacitors and mute circuits. The ADC block of the AK4688 achieves a dynamic range of 99dB, and the DAC block achieves a dynamic range of 105dB. The AK4688 is suitable for digital recording systems, digital TVs, Blu-ray recorders and Home theater systems. AK4688主要特性: Asynchronous ADC/DAC Operation Capless Stereo Pre-amplifier for Line Input/Output 24bit Stereo ADC - 64x Oversampling - Sampling Rate up to 48kHz - Linear Phase Digital Anti-Alias Filter - S/(N+D): 83dB - Dynamic Range, S/N: 99dB - Digital HPF for Offset Cancellation 24bit Stereo DAC - 128x Oversampling - Sampling Rate up to 192kHz - 24bit 8 times Digital Filter - S/(N+D): 95dB - Dynamic Range, S/N: 105dB - De-emphasis Filter High Jitter Tolerance External Master Clock Input: 256fs, 384fs, 512fs 768fs (fs=32kHz ∼ 48kHz) 128fs, 192fs, 256fs 384fs (fs=64kHz ∼ 96kHz) 128fs, 192fs (fs=128kHz ~ 192kHz) 2 Audio Serial I/F (PORT1, PORT2) - Master/Slave mode (PORT1) - I/F format PORT1, 2: MSB, LSB justified (16/24 bit), I2S Hardware / I2C-bus Control Operating Voltage: - Digital I/O and Charge Pump: 3.0V ∼ 3.6V - ADC Analog: 3.0V ∼ 3.6V - DAC Analog: 3.0V ∼ 3.6V Package: 36pin QFN 
圖1.AK4688方框圖
圖2.AK4688典型應用框圖(I2C控制模式, CAD0 引腳= “L”, 主模式)
圖3.AK4688典型應用框圖(H/W控制模式, MCLK=768fs, 主模式) 評估板AKD4688-A AKD4688-A is an evaluation board for AK4688, which is a single chip 24bit CODEC with a 2ch ADC and a 2ch DAC. It is possible to evaluate not only A/D and D/A of the AK4688, but also asynchronous operation characteristics. Also, the board could be connected to a digital’s audio equipment easily with S/PDIF connectors. 評估板AKD4688-A功能: Compatible with 2 types of digital audio interface - Optical (S/PDIF) input/output with DIT/DIR (AK4118A) - 10pin headers for interfacing with external data source Separate power supply or regulator power supply 10pin header for register control
圖4.評估板AKD4688-A框圖
圖5.評估板AKD4688-A電路圖(1)
圖6.評估板AKD4688-A電路圖(2)
圖7.評估板AKD4688-A電路圖(3)
圖8.評估板AKD4688-A電路圖(4)
圖9.評估板AKD4688-A電路圖(5)
圖10.評估板AKD4688-A電路圖(6)
圖11.評估板AKD4688-A PCB元件布局圖(頂層)
圖12.評估板AKD4688-A PCB元件布局圖(底層) 詳情請見: 
akd4688-a-01e0.pdf
(1.75 MB)
和
akd4688-a-01e.pdf
(1.75 MB)
來源：網絡 |
