SLVSHA1C September   2024  – August 2025 TPS1685

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  Parallel Device Synchronization (SWEN)
      8. 7.3.8  Stacking Multiple eFuses for Unlimited 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 (FLT)
      12. 7.3.12 Power Good Indication (PG)
      13. 7.3.13 Output Discharge
      14. 7.3.14 FET Health Monitoring
      15. 7.3.15 Single Point Failure Mitigation
        1. 7.3.15.1 IMON Pin Single Point Failure
        2. 7.3.15.2 IREF Pin Single Point Failure
        3. 7.3.15.3 ITIMER Pin Single Point Failure
    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
    2. 8.2 Typical Application: 54V Power Path Protection in Data Center Servers
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
      3. 8.2.3 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

7.3.15.2 IREF Pin Single Point Failure

  • IREF pin open or forced to higher voltage: In this case, the IREF pin (VIREF) is pulled up internally or externally to a voltage which is higher than the target value as per the recommended IOCP or ILIM calculations, preventing the primary circuit-breaker, active current limit, and short-circuit protection from getting triggered even if there is significant current flowing through the device. The device relies on an internal overcurrent detection mechanism to provide some protection as a backup. If the device detects that the backup overcurrent threshold is exceeded but at the same the primary overcurrent or short-circuit detection on IMON pin fails, single point failure detection is triggered and latches a fault. The FET is turned off and the FLT pin is asserted.
  • IREF pin shorted to GND: In this case, the VIREF threshold is set to 0V, causing the part to perform active current limit or circuit-breaker action even if there is no significant current flowing through the device.