描述 The LMH0397 is a 3G-SDI 75-Ω bidirectional I/O with integrated reclocker. This devicecan be configured either in input mode as an adaptive cable equalizer or in output mode as a dualcable driver, allowing system designers the flexibility to use a single BNC either as an input oroutput port to simplify HD-SDI video hardware designs. The integrated reclocker locks to allsupported SMPTE data rates up to 2.97 Gbps in both modes. The bidirectional I/O has an on-chip 75-Ωtermination and return loss compensation network that meets the stringent SMPTE return lossrequirements.An additional 75-Ω driver output allows the LMH0397 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 loopback 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 LMH0397 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 LMH0397 is powered from a single 2.5-V supply. The device is offered in a small 5-mm× 5-mm, 32-pin WQFN package. The LMH0397 is also pin-compatible with theLMH1297.特性 User-Configurable Adaptive Cable Equalizer or Cable Driver With IntegratedReclockerSupports ST-424 (3G), ST-292 (HD), and ST-259 (SD) CompatibleWith DVB-ASI and AES10 (MADI) Integrated Reclocker Locks to SMPTE Rates of2.97 Gbps, 1.485 Gbps, or Divide-by-1.001 Subrates and 270 MbpsOn-Chip 75-ΩTermination 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):200 m at 2.97 Gbps300 m at 1.485 Gbps600 m at 270 Mbps CD (Cable Driver) 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: 275 mW (Typical) CD Mode: 315 mW (Typical)Programmable Through Pins, SPI, or SMBusInterface–40°C to +85°C Operating TemperatureRange5-mm × 5-mm, 32-Pin WQFN PackagePin Compatible with the LMH1297 for Easy Upgrade to12G-SDIAll trademarks are the property of their respective owners.