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 , TPSM8287A15

 

  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

Further Analysis with Damped Filters

The output impedance, bode plot and load transient response of the converter are again measured after adding the parallel damping branch (Rd-Cd) with the filters.

Figure 5-1 Output Impedance Curve of the Step-Down Converter with Damped Filters
Figure 5-2 Gain Magnitude and Phase Plot of the Step-Down Converter with Damped Filters
Figure 5-3 Time-Domain Response of an Output Voltage of the Step-Down Converter Model with Damped Filters

In Figure 5-1, it can be seen that addition of the damping with the filters has helped to reduce the peak in the output impedance curve and reduces the maximum impedance value to 0.15 Ω. This damping method helps to reduce the excessive power loss also as compared to series Rd with filter as shown in Figure 4-1(b). In Figure 5-2, phase margin is also improved to 45.9° from 26° by damping the filters. Figure 5-3 shows the transient response of the device in which oscillations are properly damped. Therefore, it can be observed that the addition of the damping branch to the filters helps to dampen the filter resonance, which improves the phase margin. Furthermore, the load transient response also appears to be reasonable as compared to the transient response of the system with undamped filters.