SBOU250 November   2020 THS4567

PRODUCTION DATA  

  1. 1Trademarks
  2. 2Features
  3. 3EVM Specifications
  4. 4Power Connections
    1. 4.1 Split-Supply Operation
    2. 4.2 Single-Supply Operation
  5. 5Input and Output Connections
    1. 5.1 VOCM and VICM Input Connections
    2. 5.2 Enable Input Connections
    3. 5.3 Example EVM Configuration Using the THS4567
  6. 6 RUN-FDA-4567-EVM Schematic, Layout, and Bill of Materials
    1. 6.1 RUN-FDA-4567-EVM Layers
    2. 6.2 Bill of Materials
  7. 7References

5.1 VOCM and VICM Input Connections

The output common mode control (Vocm) can be set by using the resistor dividor created by R17 and R26, the test point TP1, or with the SMA connector J3. If providing 50-Ω termination for the Vcm input signal source is desired, C5 can be replaced with a 50-Ω resistor.

The input common mode (Vicm) can be set by using the resistor dividor created by R27 and R28, the test point TP7, or with the SMA connector J10. If providing 50-Ω termination for the Vcm input signal source is desired, C20 can be replaced with a 50-Ω resistor.

The EVM also contains a ICM EN input connection to disable or enable the input common mode control functionality. It is set to V+ by default using resistor R21 and can be shorted to V- with jumper J6. For high-speed control, C15 can be replaced with 0 Ω to terminate the PD SMA input with a 50 ohm resistor in R20. The shorting block should be removed from J7 during high-speed testing. Because 0 Ω at C10 terminates to the ground and not to the supplies. The state of the amplifier will be undefined when the signal source is disconnected. For this reason, 0 Ω at C4 should only be used when driving the SMA connector with a high speed, controlled impedance source.