SBOU262 September   2021 LMH5485-SP

 

  1.   Trademarks
  2. 1LMH5485-SP-EVM
  3. 2Features
  4. 3EVM Specifications
  5. 4Power Connections
  6. 5Split-Supply Operation
  7. 6Single-Supply Operation
  8. 7Input and Output Connections
    1. 7.1 VOCM Input Connections
    2. 7.2 PD Input Connections
    3. 7.3 Using the Optional Differential Outputs (J6 and J7)
  9. 8 LMH5485-SP Schematic and Layout
    1. 8.1 LMH5485-SP-EVM Layout
  10. 9Related Documentation

7.3 Using the Optional Differential Outputs (J6 and J7)

Figure 8-1 shows a recommended schematic configuration where balun T2 is used to convert the output to single-ended. To reconfigure the LMH5485-SP-EVM for fully-differential outputs, remove resistors R19 and R20 to disconnect the balun from the amplifier output. If 50-Ω resistors are loaded in the R26 and R27 resistor positions, and SMA connectors are loaded in the J6 and J7 connector positions, then J6 and J7 can be used for fully-differential output signals. If 50-Ω test equipment is connected to J6 and J7, then the total load to the amplifier is 200-Ω. The data sheet specifications were produced with a 500-Ω load. To match a 500-Ω load, load R26 and R27 with 221-Ω resistors and then load R25 and R28 with 60.4-Ω resistors.