Description

The MAX5855 high-performance, interpolating and modulating,16-bit, 4.9Gsps RF DAC can directly synthesize upto 1000MHz of instantaneous bandwidth from DC to frequenciesgreater than 2.45GHz. The device is optimizedfor cable access and digital video broadcast applicationsand meets spectral emission requirements for a broadset of radio transmitters and modulators including DOCSIS3.1/3.0, DVB-C/C2, DVB-T2, DVB-S2X, ISDB-T, andEPoC.The device integrates interpolation filters, a digital quadraturemodulator, a numerically controlled oscillator (NCO),clock multiplying PLL + VCO and a 14-bit RF DAC core.The 4x linear phase interpolation filter simplifies reconstructionfiltering, while enhancing passband dynamic performance,and reducing the input data bandwidth requiredfrom an FPGA. The NCO allows for fully agile modulationof the input baseband signal for direct RF synthesis.The MAX5855 input interface accepts 16-bit input data byway of a five-lane, JESD204B SerDes data input interfacethat is Subclass-0 compliant and operates at a datarate of 9.8304Gbps.The MAX5855 clock input has a flexible interface that acceptsa differential sine-wave or square-wave referenceinput clock signal at 245.75MHz, 491.52MHz, or983.04MHz. A clock multiplying PLL and VCO is used tointernally generate the 4.9152GHz sampling clock fromthe reference clock. The device provides a divided referenceclock output to ensure synchronization between thedata source and the DAC.The integrated RF DAC uses a differential current-steeringarchitecture that includes a differential 50Ω internal terminationand can produce a 3dBm full-scale output signallevel on a 50Ω external load. Operating from 1.0V and1.8V power supplies, the device consumes 2.7W at4.9Gsps. The device is offered in a compact 144-pin,10mm x 10mm, FCCSP package and is specified for theextended industrial temperature range (-40°C to +85°C).ApplicationsDigital Video Broadcast ModulatorsDOCSIS 3.1/3.0 Remote PHY and CCAPDVB-C/C2/DVB-T2/DVB-S2X/ISDB-TEthernet PON over Coax (EPoC)InstrumentationPoint-to-Point Wireless