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

Abstract

This application note explains and demonstrates two different over-current protection mechanisms that the different eFuse devices provide. One is called current-limit, and another is circuit-breaker. Using experimental results, this article also discusses the limitations of the current-limit-based over-current protection in enterprise server applications, where the power delivery system is exposed to high slew-rate, high frequency, and high amplitude load transients. The limitations of the approach as mentioned above are solved through the circuit-breaker mechanism along with a programmable over-current blanking timer in TI’s high-current eFuse family of devices. This design is discussed in this application note through experimental results. The system-level benefits of using TI’s high-current eFuse design over the conventional eFuse devices available in the market are also discussed.