描述 The LMH1297 is a 12G UHD-SDI 75-Ω bidirectional I/O with integrated reclocker. Thisdevice can be configured either in input mode as an adaptive cable equalizer or in output mode as adual cable driver, allowing system designers the flexibility to use a single BNC either as an inputor output port, simplifying UHD video hardware designs. The integrated reclocker locks to allsupported SMPTE data rates up to 11.88 Gbps in both modes. The bidirectional I/O has an on-chip75-Ω termination and return loss compensation network that meets the stringent SMPTE return lossrequirements.An additional 75-Ω driver output allows the LMH1297 to support a variety of systemfunctions. In EQ (Equalizer) Mode, this second 75-Ω driver can be used as a loop-through output. InCD (Cable Driver) Mode, this 75-Ω driver can be used as a second fan-out cable driver. Thehost-side 100-Ω driver can also be used as a loop-back output in CD Mode for monitoringpurposes.The on-chip reclocker attenuates high-frequency jitter and fully regenerates the datausing a clean, low-jitter clock. The reclocker has a built-in loop filter and does not require anyinput reference clock. The LMH1297 also has an internal eye opening monitor and a programmable pinfor CDR lock indication, input carrier detect, or hardware interrupts to support system diagnosticsand board bring-up. The LMH1297 is powered from a single 2.5-V supply. It is offered in a small 5-mm × 5-mm,32-pin QFN package.特性 User-Configurable Adaptive Cable Equalizer or Cable Driver With IntegratedReclockerSupports ST-2082-1 (12G), ST-2081-1 (6G), ST-424 (3G), ST-292 (HD), and ST-259 (SD) Compatible With DVB-ASI andAES10 (MADI) Integrated Reclocker Locks to SMPTE Rates of 11.88 Gbps, 5.94Gbps, 2.97 Gbps, 1.485 Gbps, or Divide-by-1.001 Sub-Rates and 270 Mbps On-Chip 75-Ω Termination and Return Loss Compensation NetworkEQ (Equalizer)Mode: Adaptive Cable Equalizer With Integrated Reclocker100-Ω Output Driver With De-EmphasisReclocked 75-Ω Loop-Through OutputEQMode Cable Reach (Belden 1694A, SDI_OUT Disabled):75 m at 11.88 Gbps 120 m at 5.94 Gbps200 m at 2.97 Gbps300 m at 1.485 Gbps600 m at 270 Mbps Cable Driver (CD) Mode: Dual Differential Output Cable Drivers With IntegratedReclockerAdaptive PCB Input EqualizerReclocked 100-Ω Loopback Output Automatic Pre-Emphasis and SlewRate Control on 75-Ω Outputs Polarity Inversion on 75-Ω and 100-ΩOutputsAutomatic Power Save in Absence of Input SignalPower Dissipation: 25 mW (Typical)Power-Down Control Through ENABLEPin Single 2.5-V SupplyEQ Mode Power Dissipation: 275 mW (Typical)CD Mode Power Dissipation: 305 mW (Typical)Programmable Through Pins, SPI, or SMBusInterface–40°C to +85°C Operating TemperatureRange5-mm × 5-mm, 32-pin QFNPackageAll trademarks are the property of their respective owners.