原标题：AKM AK4686多路音频CODEC解决方案

　　akm公司的 AK4686是多路音频CODEC,包括了一个立体声ADC和两个立体声DAC以及6:1无电容输入选择器和线路驱动驱动器. ADC/DAC接口支持24位输入数据和异步操作.ADC的动态范围96dB,DAC的动态范围100dB,主要用在数字电视(DTV)和家庭影响系统.本文介绍了AK4686主要特性,方框图,典型应用电路以及AKD4686-B评估板功能,方框图以及详细电路图和元件布局图.

　　AK4686:Multi-channel CODEC with Capless Stereo Selector

　　The AK4686 is a single chip audio CODEC that includes one stereo ADC and two stereo DACs in addition to the input selector and the line drivers. The interfaces of ADC/DAC can accept up to 24bit input data and support asynchronous operation. Both the input stereo selector and output drivers support ground reference I/O to remove AC-coupling capacitors and reducing external parts. The AK4686 has a dynamic range of 96dB for ADC, 100dB for DAC, and it is well suitable for digital TV and Home theater systems.

　　AK4686主要特性:

　　Asynchronous Operation between Port 1(ADC and DAC1) and Port 2 (DAC2)

　　6:1 Capless Stereo Line Input Selector

　　24bit Stereo ADC

　　- 64x Oversampling

　　- Sampling Rate up to 48kHz

　　- Linear Phase Digital Anti-Alias Filter

　　- S/(N+D): 88dB

　　- Dynamic Range, S/N: 96dB

　　- Digital HPF for Offset Cancellation

　　24bit Two Stereo DAC

　　- 128x Oversampling

　　- Sampling Rate up to 192kHz

　　- 24bit 8 times Digital Filter

　　- S/(N+D): 88dB

　　- Dynamic Range, S/N: 100dB

　　- De-emphasis Filter

　　- Analog Soft Mute

　　High Jitter Tolerance

　　TTL Level Digital I/F

　　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

　　PORT2: MSB, LSB justified (16/24 bit), I2S

　　PORT1: MSB, LSB justified (16/24 bit), I2S

　　I2C Bus μP I/F for mode setting

　　Operating Voltage:

　　- Digital I/O: 3.0V ∼ 3.6V

　　- Charge Pump: 3.0V ∼ 3.6V

　　- Analog: 3.0V ∼ 3.6V

　　Package: 48pinLQFP

　　图1.AK4686方框图

　　图2.AK4686典型连接框图(从模式)

　　AKD4686-B评估板

　　AKD4686-B is an evaluation board for AK4686, a single chip 24bit CODEC that has one stereo ADC and two stereo DAC. This board has interfaces with AKM’s evaluation boards for A/D converter and D/A converter and makes easy to evaluate AK4686. Also this board has the digital audio interface and then achieves the interface with digital audio systems via RCA connector.

　　AKD4686-B评估板功能:

　　On-board clock generators (AK4118 x 2)

　　Compatible with 2 types of digital audio interface

　　- RCA (S/PDIF) input/output

　　- 10pin headers for interfacing with external data source (x2)

　　RCA connectors for clock input with external clock source

　　10pin header for register control

　　图3.AKD4686-B评估板方框图