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

7.3.5 Analog Load Current Monitor (IMON)

The TPS1686x allows the system to monitor the output load current accurately by providing an analog current on the IMON pin which is proportional to the current through the FET. The benefit of having a current output is that the signal can be routed across a board without adding significant errors due to voltage drop or noise coupling from adjacent traces. The IMON signal can be converted to a voltage by dropping the voltage across a resistor at the point of monitoring. The user can sense the voltage (VIMON) across the RIMON to get a measure of the output load current using Equation 9.

Equation 9. I O U T = V I M O N G I M O N × R I M O N

The TPS1686x IMON circuit is designed to provide high bandwidth and high accuracy across load and temperature conditions, irrespective of board layout and other system operating conditions. This design allows the IMON signal to be used for advanced dynamic platform power management techniques such as Intel PSYS or PROCHOT# to maximize system power usage and platform throughput without sacrificing safety or reliability.

TPS1686 Analog Load Current Monitor Response Figure 7-4 Analog Load Current Monitor Response
Note:

  1. The IMON pin provides load current monitoring information only during steady-state. During inrush, the IMON pin reports zero load current.

  2. The ILIM pin reports the device load current at all times and can also be used as an analog load current monitor for the device.
  3. Care must be taken to minimize parasitic capacitance on the IMON and ILIM pins to avoid any impact on the overcurrent and short-circuit protection timing.