原标题：AKM AK4414 32位ADC DVD音频解决方案

　　akm 公司的AK4414是32位ADC,包括最近开发的32位8x数字滤波器, 具有更好的音质,更低失真和更宽动态范围,128x过采样,采样速率30kHz到216kHz,采用216kHz PCM数据和蔼1比特DSD数据,非常适合包括DVD音频和SACD在内的各种应用.本文介绍了AK4414主要特性,框图以及评估板AKD4414- SA 主要功能和电路图.

　　AK4414 is a 32-bit DAC, which corresponds to BD systems. An internal circuit includes newly developed 32bit Digital Filter for better sound quality achieving low distortion characteristics and wide dynamic range. The AK4414 has full differential SCF outputs, removing the need for AC coupling capacitors and increasing performance for systems with excessive clock jitter. The AK4414 accepts 216kHz PCM data and 1-bit DSD data, ideal for a wide range of applications including DVD-Audio and SACD.

　　AK4414主要特性:

　　• 128x Over sampling

　　• Sampling Rate: 30kHz ∼ 216kHz

　　• 32Bit 8x Digital Filter

　　- Ripple: ±0.005dB, Attenuation: 80dB

　　- High Quality Sound Short Delay Option; GD=7/fs and GD=5.5/fs

　　- Sharp Roll-Off Filter

　　- Slow Roll-Off Filter

　　• High Tolerance to Clock Jitter

　　• Low Distortion Differential Output

　　• DSD data input

　　• Digital De-emphasis for 32, 44.1, 48kHz sampling

　　• Soft Mute

　　• Digital Attenuator (255 levels and 0.5dB step)

　　• Stereo Mode

　　• THD+N: -107dB

　　• DR, S/N: 120dB (Stereo mode: 123dB)

　　• I/F Format: 24/32bit MSB justified, 16/20/24/32bit LSB justified, I2S, DSD, TDM

　　• Master Clock:

　　30kHz ~ 32kHz: 1152fs

　　30kHz ~ 54kHz: 512fs or 768fs

　　30kHz ~ 108kHz: 256fs or 384fs

　　108kHz ~ 216kHz: 128fs or 192fs

　　• Power Supply: DVDD=AVDD=2.7 ∼ 3.6V, VDD1/2=4.75 ∼ 5.25V

　　• Digital Input Level: CMOS

　　• Package: 44pin LQFP

　　图1. AK4414方框图

　　评估板AKD4414-SA

　　The AKD4414-SA is an evaluation board for AK4414, 32bit 4ch DAC, supporting DVD-Audio. The AKD4414-SA has digital audio interfaces, enabling to interface to digital audio systems via optical or coaxial connector.

　　评估板AKD4414-SA 主要功能:

　　 Three digital audio interfaces

　　- Coaxial Input

　　- Optical Input

　　- 10pin Header for serial control mode

　　 USB control port

　　 On-board Analog output buffer circuit

　　图2. 评估板AKD4414-SA 框图