SLAA719 August   2016 TPA3221 , TPA3244 , TPA3245 , TPA3250 , TPA3251 , TPA3255 , TPA3255-Q1

 

  1.   TPA32xx Analog Input Grounding for Single Ended Inputs
    1.     Trademarks
    2. 1 Single Ended to Differential Input Stage
    3. 2 Input Stage with Ground Plane
      1. 2.1 Testing Ground Plane Configuration
      2. 2.2 Ground Plane Results
    4. 3 Input Stage with Star Ground
      1. 3.1 Testing Star Ground Configuration
    5. 4 TPA32xx Ground Pin Reference

3.1 Testing Star Ground Configuration

Using this star ground topology of Figure 7, the THD+N vs output power of the TPA3244 amplifier was again tested by running 2 channels in BTL with 4 Ω loads at 100 Hz.

Not only is the amplifier channel performance now matched, but the overall THD+N has improved. Ground noise is no longer affecting our input stage.

D004_SLAA719.gifFigure 7. TPA3244 THD+N vs Power 100 Hz Star Ground