SNLA299 August   2018 LMH0324 , LMH0397 , LMH1208 , LMH1218 , LMH1219 , LMH1297

 

  1.   LMH12xx MADI Compatibility Application Note
    1.     Trademarks
    2. 1 MADI Specification Requirements
      1. 1.1 MADI Transmitter Electrical Requirements
        1. 1.1.1 Line Driver Impedance
        2. 1.1.2 Mean Output Voltage
        3. 1.1.3 Maximum Output Voltage
        4. 1.1.4 Terminated Signal Rise and Fall Time
      2. 1.2 MADI Receiver Electrical Requirements
    3. 2 LMH12xx Device Family
      1. 2.1 LMH12xx Device Family
        1. 2.1.1 LMH1297 MADI Modes of Operation
          1. 2.1.1.1 Dual MADI Cable Driver
          2. 2.1.1.2 SDI Bidirectional IO and MADI Cable Driver
          3. 2.1.1.3 Bidirectional MADI Port and SDI MADI Cable Driver
          4. 2.1.1.4 Bidrectional MADI Port and SDI Cable Driver
        2. 2.1.2 LMH1297 Device Family Register Changes for MADI Compatibility
        3. 2.1.3 LMH1297 Device Family Hardware Changes for MADI Compatibility
      2. 2.2 LMH1218 Device Family Hardware Changes to Support MADI Compatibility
      3. 2.3 LMH1219 Device Family Recommended Register Settings
    4. 3 Summary
    5. 4 References

3 Summary

the LMH1297 device family provides different options to meet MADI requirements. These options are:

  • Dual MADI Cable Drivers
  • SDI_IO bidirectional SDI plus MADI cable driver
  • SDI_IO bidirectional MADI with MADI cable driver
  • SDI_IO bidirectional IO MADI with SDI cable driver

To meet these requirements, new register settings and a 10-pF capacitor must be added across SDI positive and negative pins.

The LMH1219 and LMH0324 require register settings to bypass retimer and thus reducing power consumption, and the LMH1218 MADI compatibility requires hardware changes and register settings to bypass retime function.