SLVSHR9 December   2024 TPS25984B

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Logic Interface
    7. 6.7 Timing Requirements
    8. 6.8 Switching Characteristics
    9. 6.9 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Undervoltage Protection
      2. 7.3.2  Insertion Delay
      3. 7.3.3  Overvoltage Protection
      4. 7.3.4  Inrush Current, Overcurrent, and Short-Circuit Protection
        1. 7.3.4.1 Slew Rate (dVdt) and Inrush Current Control
          1. 7.3.4.1.1 Start-Up Time Out
        2. 7.3.4.2 Steady-State Overcurrent Protection (Circuit-Breaker)
        3. 7.3.4.3 Active Current Limiting During Start-Up
        4. 7.3.4.4 Short-Circuit Protection
      5. 7.3.5  Analog Load Current Monitor (IMON)
      6. 7.3.6  Mode Selection (MODE)
      7. 7.3.7  Digital Overcurrent Indication (D_OC)
      8. 7.3.8  Stacking Multiple eFuses for Scalability
        1. 7.3.8.1 Current Balancing During Start-Up
      9. 7.3.9  Analog Junction Temperature Monitor (TEMP)
      10. 7.3.10 Overtemperature Protection
      11. 7.3.11 Fault Response and Indication (GOK/FLT)
      12. 7.3.12 Power-Good Indication (PG)
      13. 7.3.13 Output Discharge
      14. 7.3.14 FET Health Monitoring
    4. 7.4 Device Functional Modes
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Single Device, Standalone Operation
      2. 8.1.2 Multiple Devices, Parallel Connection
      3. 8.1.3 Digital Telemetry Using External Microcontroller
    2. 8.2 Typical Application: 12V, 3.3kW Power Path Protection in Data Center Servers
      1. 8.2.1 Application
      2. 8.2.2 Design Requirements
      3. 8.2.3 Detailed Design Procedure
      4. 8.2.4 Application Curves
    3. 8.3 Power Supply Recommendations
      1. 8.3.1 Transient Protection
      2. 8.3.2 Output Short-Circuit Measurements
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.3.4.4 Short-Circuit Protection

During an output short-circuit event, the current through the device increases very rapidly. When an output short-circuit is detected, the internal fast-trip comparator triggers a fast protection sequence to prevent the current from building up further and causing any damage or excessive input supply droop. The fast-trip comparator employs a scalable threshold (ISFT) which is equal to 2 × IOCP during steady-state and 1.5 × ILIM during inrush. This action enables the user to adjust the fast-trip threshold as per system rating, rather than using a high fixed threshold which can not be suitable for all systems. After the current exceeds the fast-trip threshold, the TPS25984Bx turns off the FET within tSFT. The device also employs a higher fixed fast-trip threshold (IFFT) to provide fast protection against hard short-circuits during steady-state (FET in linear region). After the current exceeds IFFT, the FET is turned off completely within tFFT. Figure 7-5 illustrates the short-circuit response for TPS25984Bx eFuse.

In some of the systems, for example blade servers and telecom equipment which house multiple hot-pluggable blades or line cards connected to a common supply backplane, there can be transients on the supply due to switching of large currents through the inductive backplane. This can result in current spikes on adjacent cards which can potentially be large enough to trigger the fast-trip comparator of the eFuse. The TPS25984Bx uses a proprietary algorithm to avoid nuisance tripping in such cases thereby facilitating uninterrupted system operation.

After the part shuts down due to a short-circuit fault, it either stays latched off (TPS25984B2 variant with MODE pin floating or TPS25984B0/3 variants) or restarts automatically after a fixed delay (TPS25984B2 variant with MODE pin connected to GND or TPS25984B1 variant).

TPS25984B Short-Circuit ResponseFigure 7-5 Short-Circuit Response