SLYT863 April   2025 LM5066I

 

  1.   1
  2. 1 Introduction
  3. 2 3
  4. 3 Challenges in designing a hot-swap circuit for a 48V AI server
  5. 4 Challenge No. 1: Turnoff delay during an output short-circuit
  6. 5 Challenge No. 2: False gate turn-off during a load transient
  7. 6 Challenge No. 3: Parallel resonance during controlled (slow) turn-on
  8. 7 Proposed circuit enhancements
  9. 8 Improving the turn-off response
  10. 9 Overcoming false turn-off for dynamic loads
  11. 10Damping parasitic oscillations
  12. 11Design guidelines and component selection
  13. 12Cdv/dt discharge circuit
  14. 13Conclusion
  15. 14References
  16. 15Related Websites

10 Damping parasitic oscillations

Adding a damping resistor (RG1, RG2, RG3) in series with the gate of each MOSFET can eliminate the parasitic oscillations in the system. Usually, we recommend a 10Ω 0603 package resistance, but based on the parasitics, a low value around 1Ω may also help. We suggest testing on your PCB and deciding the value of the damping resistor.