SLVSHR6A July   2025  – November 2025 TPS1686

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  Switch Enable Pin (SWEN)
      7. 7.3.7  Analog Junction Temperature Monitor (TEMP)
      8. 7.3.8  Overtemperature Protection
      9. 7.3.9  Fault Response and Indication (FLT)
      10. 7.3.10 Power Good Indication (PG)
      11. 7.3.11 Output Discharge
      12. 7.3.12 FET Health Monitoring
      13. 7.3.13 Single Point Failure Mitigation
        1. 7.3.13.1 IMON Pin Single Point Failure
        2. 7.3.13.2 IREF Pin Single Point Failure
        3. 7.3.13.3 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. 8.2 Typical Application: 54V Fan Load Protection in Datacenter Servers
      1. 8.2.1 Application
      2. 8.2.2 Design Requirements
      3. 8.2.3 Detailed Design Procedure
      4. 8.2.4 Application Performance Plots
    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 Third-Party Products Disclaimer
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

7.3.1 Undervoltage Protection

The TPS1686x implements Undervoltage Lockout on VDD and VIN in case the applied voltage becomes too low for the system or device to properly operate. The Undervoltage lockout has a default lockout threshold of VUVP internally on VDD and VUVPIN on VIN. Also, the UVLO comparator on the EN/UVLO pin allows the Undervoltage Protection threshold to be externally adjusted to a user defined value. The following figure and equation show how a resistor divider can be used to set the UVLO set point for a given voltage supply.

TPS1686 Adjustable Undervoltage ProtectionFigure 7-1 Adjustable Undervoltage Protection
Equation 1. V I N U V = V U V L O R R 1 + R 2 R 2

The EN/UVLO pin implements a bi-level threshold.

  1. VEN > VUVLO(R): Device is fully ON.
  2. VSD(F) < VEN < VUVLO(F): The FET along with most of the controller circuitry is turned OFF, except for some critical bias and digital circuitry. Holding the EN/UVLO pin in this state for > tQOD activates the Output Discharge function.
  3. VEN < VSD(F): All active circuitry inside the part is turned OFF and the device retains no digital state memory. The circuitry also resets any latched faults. In this condition, the device quiescent current consumption is minimal.