SLVAFE0 February   2023 TPS62441-Q1 , TPS62442-Q1 , TPS62810-Q1 , TPS62811-Q1 , TPS62812-Q1 , TPS62813-Q1 , TPS628501-Q1 , TPS628502-Q1 , TPS628503-Q1 , TPS62870 , TPS62870-Q1 , TPS62871 , TPS62871-Q1 , TPS62872 , TPS62872-Q1 , TPS62873 , TPS62873-Q1 , TPS62874-Q1 , TPS62875-Q1 , TPS62876-Q1 , TPS62877-Q1 , TPSM8287A06 , TPSM8287A12

 

  1.   Abstract
  2.   Trademarks
  3. 1Overview
  4. 2Detailed Description
    1. 2.1 Input Filter Design
    2. 2.2 Output Filter Design (Second Stage)
  5. 3Measurement and Analysis
  6. 4Damping of the Filters
  7. 5Further Analysis with Damped Filters
  8. 6Conclusion
  9. 7Reference

2.2 Output Filter Design (Second Stage)

Second stage of the output filter is used in general to improve the ripple performance of the device for applications which are more sensitive to variations in an output voltage. The maximum impedance limit Zout,max of the second stage of filter can be determined with Equation 8.

Equation 8. Z o u t , m a x = Δ V o u t Δ I

In Equation 8, ΔVout is the maximum allowed variation in output voltage which is taken five percent of the output voltage for this design and ΔI is the maximum change in output current which is 1-A. The cut-off frequency chosen for the second stage of an output filter is 79 kHz and calculated maximum impedance limit is 0.17 Ω. After inserting these values in Equation 7, it gives the minimum capacitance limit of 12 μF and maximum inductance of 340 nH. These values are selected for the second stage of the output filter as Lf,out and Cf,out.