AD9878: 低成本、3.3 V、CMOS混合信号前端(MxFE®),适合宽带应用

AD9878 功能框图AD9878是一款单电源电缆调制解调器/机顶盒混合信号前端,内置发射路径插值滤波器、完整正交数字上变频器和发射DAC。接收路径内置双通道12位ADC和10位ADC。内部需要的所有时钟和输出系统时钟均由PLL从单晶振或时钟输入产生。发射路径插值滤波器提供16倍的升采样系数,输出信号带宽最高可达5.8 MHz。直接数字频率合成器(DDS)可以产生最高65 MHz的载波频率,调谐分辨率为26位。发射DAC的分辨率为12位,能以高达232 MSPS的采样速率工作。模拟输出可以在0 dB至7.5 dB范围内调整,步进为0.5 dB,以便在输出电平需要降低时保持信噪比(SNR)性能。12位ADC提供出色的欠采样性能,使该器件可提供10个以上的有效位数(ENOB),中频输入最高可达70 MHz。12位中频ADC的采样速率最高可达29 MHz,因而能处理宽带信号。

The AD9878 is a single-supply cable modem/set-top box mixed-signal front end. The device contains a transmit path interpolation filter, a complete quadrature digital upconverter, and transmit DAC. The receive path contains dual, 12-bit ADCs and a 10-bit ADC. All internally required clocks and an output system clock are generated by the PLL from a single crystal oscillator or clock input.The transmit path interpolation filter provides an upsampling factor of 16 x with an output signal bandwidth up to 5.8 MHz. Carrier frequencies up to 65 MHz with 26 bits of frequency tuning resolution can be generated by the direct digital synthesizer (DDS). The transmit DAC resolution is 12 bits and can run at sampling rates as high as 232 MSPS. Analog output scaling from 0 dB to 7.5 dB in 0.5 dB steps is available to preserve SNR when reduced output levels are required.The 12-bit ADCs provide excellent undersampling performance, allowing this device to deliver better than 10 ENOBs with IF inputs up to 70 MHz. The 12-bit IF ADCs can sample at rates up to 29 MHz, allowing them to process wideband signals.The AD9878 includes a programmable sigma-delta DAC, which can be used to control an external component such as a variable gain amplifier (VGA)or a voltage controlled tuner. The AD9878 also integrates a CA port that enables a host processor to interface with the AD8321/AD8323 or AD8322/AD8327/AD8328 programmable gain amplifier (PGA) cable drivers via the MxFE serial port (SPORT).

AD9878 特点
  • 低成本3.3 V CMOS MxFE®,适合宽带应用
  • 232 MHz正交数字上变频器
  • 12位直接中频DAC (Txdac+®)
  • 最高65 MHz载波频率DDS
  • 可编程采样时钟速率
  • 模拟发射输出电平可调
  • 双通道12位、29 MSPS直接中频ADC,具有视频箝位输入
  • 10位、29 MSPS采样ADC
  • 8位Σ-Δ型辅助DAC
  • 可与AD8321/AD8323或AD8322/AD8327 PGA电缆驱动器直接接口
AD9878 技术指标
  • Resolution (Bits): 12bit
  • # Chan: 4
  • Sample Rate: 29MSPS
  • Interface: Par
  • Analog Input Type: Diff-Uni
  • Ain Range: 2 V p-p
  • ADC Architecture: Pipelined
  • Pkg Type: QFP
AD9878 芯片订购指南
产品型号 封装 引脚 温度范围 包装和数量 报价*(100-499) 报价*1000 pcs RoHS
AD9878BSTZ 产品状态: 量产 100 ld LQFP 100 工业 Tray, 90 $ 16.10 $ 13.68
AD9878 应用技术支持与电子电路设计开发资源下载
  1. AD9878 数据手册DataSheet下载 .pdf
  2. Analog Devices, Inc.ADI 美国模拟器件公司产品订购手册 .pdf
  3. ADC模数转换器选型指南 .pdf