SLVAFR8 January   2025 TPS1685 , TPS1689 , TPS25984 , TPS25984B , TPS25985 , TPS25990

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2Over-Current Response of Conventional eFuse Devices
  6. 3Challenges with Current Limit Functionality
  7. 4Proposed Design Using TI's High-Current eFuses
    1. 4.1 Steady-State Over-Current Protection in TPS25984, TPS25985, TPS25990, and TPS1685 eFuses
    2. 4.2 Design Guideline
  8. 5Thermal Performance with Continual Transient Load Current
  9. 6System Level Advantages with TI's eFuse Design
    1. 6.1 Lower Number of eFuses to be Connected in Parallel
    2. 6.2 Reduced PSU Size
  10. 7Summary
  11. 8References

7 Summary

This application note discusses the system-level benefits of using TI’s high current eFuses over the other existing eFuses or hot-swap controller designs in the context of over-current protection and transient overload conditions for an enterprise server motherboard. The circuit breaker mechanism and a programmable over-current blanking timer feature greatly reduce the total system cost. It improves the power density by reducing the number of high-current-carrying power components in parallel or their size and the PCB copper trace thickness. This is because of the reduction of the overall RMS current rating of the system. Using TI’s high-current eFuse designs, the input PSU rating is optimized to the TDC rating of the system, instead of making it rated for the peak pulse current rating of the system. Therefore, the system power utilization is greatly enhanced.