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IDT公司的ACS422x00是低功耗高保真24位立體聲CODEC.器件還集成了DDX D類揚聲器放大器,真正無電容的耳機放大器和四個可編程的系統PLL.其中的DAC具有102dB SNR, THD+N優于-82dB,而ADC具有90dB SNR, HD+N優于-80dB.器件具有3D立體聲增強效果,1W時的效率大于80%,主要用在平板電腦,PND,PMP,手提投映儀和音箱等.本文介紹了ACS422x00主要特性,方框圖, 輸出和輸入音頻處理框圖以及參考設計電路圖. PORTABLE CONSUMER CODEC LOW-POWER, HIGH-FIDELITY INTEGRATED CODEC The ACS422x00 is a low-power, high-fidelity integrated CODEC targeted at portable applications such as tablet computers, personal navigation devices, portable projectors and speaker docks. In addition to a high-fidelity low-power CODEC, the device integrates a DDXTM class-D speaker amplifier, a true cap-less headphone amplifier, and four programmable system PLLs to enable the timing management of the systems applications processor, USB interface, secondary audio and other subsystems. Beyond high-fidelity for portable systems, the device offers an enriched “audio presence” through built-in audio processing capability The ACS422x00 has been designed with rapid customization in mind. IDT is able to rapidly provide varying levels of integration, additional audio processing, more or fewer PLLs, etc, according to the needs of large markets or customers. ACS422x00主要特性: • High fidelity 24-bit stereo CODEC • DAC 102dB SNR; THD+N better than -82dB • ADC 90dB SNR, THD + N better than -80dB • Built in audio controls and processing • 3D stereo enhancement • Dual (cascaded) stereo 6-band parametric equalizers • Programmable Compressor/Limiter/Expander • Psychoacoustic Bass and Treble enhancement processing • Filterless Stereo DDXTM Class D Speaker Driver • 1W/channel (8ohm) or 2W/channel (4 ohm), 0.05% THD+N typical • Tri-state DDXTM Class D achieves low EMI and high efficiency • >80% efficiency at 1W • Spread spectrum support for reduced EMI output power mode • Anti-Pop circuitry • On-chip true cap-less headphone driver • 40 mW output power (16ohm) • Charge-pump allows true ground centered outputs • SNR of 102dB • I2S data interface • Microphone/line-in interface • Analog microphone or line-in inputs • Digital microphone (ACS422D00) • Automatic level control • 4 on-chip low-jitter PLLs for internal and system timing • Multiple frequency options • Spread spectrum support • Low power with built in power management • 1.7 V CODEC supports 1Vrms • Very low standby and no-signal power consumption • 1.8V digital / 1.7V analog supply for low power • 2-wire (I2C compatible) control interface • 68-pin dual row 6x6 mm Thermal Leadless Array package ACS422x00目標應用: • Tablet Computers • Portable Navigation Devices • Personal Media Players • Portable Projectors • Speaker Docks 
圖1.ACS422x00方框圖
圖2.ACS422x00輸出音頻處理框圖
圖3.ACS422x00輸入音頻處理框圖
圖4.ACS422x00參考設計電路圖(1)
圖5.ACS422x00參考設計電路圖(2)
圖6.ACS422x00參考設計電路圖(3) 詳情請見: http://www.idt.com/?app=search&searchType=document&cat=1&category=7233908&docTypeCat=0# 和 LTER=0&SUBQUERYKEYWORD=&SEARCHTYPE=document&DOCTYPECAT=0&CATEGORY=7233908&NUMRESULTS=0&GENPART=&SEARCH=&DOCTYPE=0&APP=search" target="_blank">http://www.idt.com/?pageNum=3&CAT=1&FILTER=0&SUBQUERYKEYWORD=&SEARCHTYPE=document&DOCTYPECAT=0&CATEGORY=7233908&NUMRESULTS=0&GENPART=&SEARCH=&DOCTYPE=0&APP=search# |
