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

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In this article, we’ll discuss various challenges that AI-based processors bring into 48V server designs, along with design guidelines and important tips and tricks for the design and layout to achieve a reliable hot-swap solution for the system specifications outlined in Table 1.

Table 1 Typical system specifications.
Design Parameter Value
Input voltage range 40V to 60V
Output capacitance 4.2mF
Steady-state thermal design power rating 6kW
Transient power rating 8kW at 400µs
Transient load profile 15% to 100% of the transient power rating with a 10% duty cycle
Load slew rate >2A/µs
Frequency of transient load >1kHz