SLVAFD4 February   2024 TPS54308 , TPS54320 , TPS54350 , TPS54620 , TPS54622 , TPS54821 , TPS54824 , TPS62933F

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Components Selection for Secondary Stage Filter
  6. 3Experimental Validation
  7. 4How to Estimate Inductance of Ferrite Bead for Ripple Reduction
  8. 5Summary
  9. 6References
  10. 7Appendix

Appendix

For easy validation, the components value L, Co and L2 are fixed and given first. The limits of C2 are calculated with Equation 7 and verified by experiments.

Vin (V) Vo (V) fsw (kHz) L (uH) Co (uF) L2 (nH) Required Ripple (mV) C2 Low Limit (uF) C2 selection (uF) Measured Ripple (mV)
12 1.2 1000 1 47 20 1 3.64 4.7 <0.8
12 1.6 1000 1.5 47 20 1 3.11 4.7 <0.8
24 1.2 500 2.2 47 20 1 27.96 30 <0.8
24 1.6 500 3.3 47 20 1 24.44 30 <0.8