SLOA339 July   2024 TAS2764 , TAS2764 , TAS2780 , TAS2780 , TAS2781 , TAS2781

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
    1. 1.1 Capacitor Only Connected at the Class-D Outputs
    2. 1.2 LC Filter Connected at the Class-D Outputs
    3. 1.3 Ferrite Bead Filters
  5. 2EMI Filter Considerations
    1. 2.1 Impedance Consideration of EMI Filter
    2. 2.2 Device Reliability Constraint for High Output Voltage
    3. 2.3 EMI Filter Current Reliability
  6. 3Post Filter Feedback
  7. 4Loop Stability With Post Filter Feedback
  8. 5User Guide: EMI Filter Modeling and Post Filter Feedback Validation Tool
  9. 6Summary
  10. 7References

6 Summary

This application note describes the different type options available for EMI filtering of the Class-D output and describes the pros and cons of each of them. Specific care-abouts related to use of EMI filters are also detailed. The Post Filter Feedback (PFFB) feature in TAS27XX family of devices is explained and the loop stability constraints are covered in detail with relevant equations. Finally, a user guide for EMI FILTER modeling and excel based post filter feedback stability validation tool is provided to help the user select an appropriate filter configuration by simply providing some inputs from the ferrite bead data sheet