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

1.2 MADI Receiver Electrical Requirements

MADI specification—unlike SDI—calls for minimum eye opening of 6 ns or 0.75 UI. Also, minimum vertical eye opening is 150 mV. Figure 1 through Figure 3 show a 6-ns horizontal eye opening. a variety of 75-Ω cables.

NOTE

For these eye diagrams, a MADI cable driver with 1-nS rise/fall time and 600-mV output swing was used. Thus, the cable lengths noted below are the maximum reach for each cable model or cable type with a 6-ns minimum vertical eye opening. For other cable types, it is proportional to the insertion loss at Nyquist frequency.

100m-B1694A.pngFigure 1. 100-m B1694A 6-ns Minimum Eye Opening
120m-5cfb.pngFigure 3. 120-m 5.5CFB 6-ns Minimum Eye Opening
150m-5cuhd.pngFigure 2. 150-m 5.5CUHD 6-ns Minimum Eye Opening