SLVSGG3A May   2022  – September 2022 TPS25985

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Logic Interface
    7. 7.7 Timing Requirements
    8. 7.8 Switching Characteristics
    9. 7.9 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Undervoltage Protection
      2. 8.3.2  Insertion Delay
      3. 8.3.3  Overvoltage Protection
      4. 8.3.4  Inrush Current, Overcurrent, and Short-Circuit Protection
        1. 8.3.4.1 Slew rate (dVdt) and Inrush Current Control
          1. 8.3.4.1.1 Start-Up Time Out
        2. 8.3.4.2 Steady-State Overcurrent Protection (Circuit-Breaker)
        3. 8.3.4.3 Active Current Limiting During Start-Up
        4. 8.3.4.4 Short-Circuit Protection
      5. 8.3.5  Analog Load Current Monitor (IMON)
      6. 8.3.6  Mode Selection (MODE)
      7. 8.3.7  Parallel Device Synchronization (SWEN)
      8. 8.3.8  Stacking Multiple eFuses for Unlimited Scalability
        1. 8.3.8.1 Current Balancing During Start-Up
      9. 8.3.9  Analog Junction Temperature Monitor (TEMP)
      10. 8.3.10 Overtemperature Protection
      11. 8.3.11 Fault Response and Indication (FLT)
      12. 8.3.12 Power Good Indication (PG)
      13. 8.3.13 Output Discharge
      14. 8.3.14 General Purpose Comparator
      15. 8.3.15 FET Health Monitoring
      16. 8.3.16 Single Point Failure Mitigation
        1. 8.3.16.1 IMON Pin Single Point Failure
        2. 8.3.16.2 ILIM Pin Single Point Failure
        3. 8.3.16.3 IREF Pin Single Point Failure
        4. 8.3.16.4 ITIMER Pin Single Point Failure
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Single Device, Standalone Operation
      2. 9.1.2 Multiple Devices, Parallel Connection
    2. 9.2 Typical Application: 12-V, 3.6-kW Power Path Protection in Datacenter Servers
      1. 9.2.1 Application
      2. 9.2.2 Design Requirements
      3. 9.2.3 Detailed Design Procedure
      4. 9.2.4 Application Performance Plots
    3. 9.3 Multiple eFuses, Parallel Connection with PMBus
    4. 9.4 Digital Telemetry Using External Microcontroller
    5. 9.5 What to Do and What Not to Do
  10. 10Power Supply Recommendations
    1. 10.1 Transient Protection
    2. 10.2 Output Short-Circuit Measurements
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Receiving Notification of Documentation Updates
    3. 12.3 Support Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.3.5 Analog Load Current Monitor (IMON)

The TPS25985x 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 current output also allows the IMON pins of multiple TPS25985x devices to be tied together to get the total current in a parallel configuration. The IMON signal can be converted to a voltage by dropping it 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 13.

Equation 13. IOUT=VIMONGIMON×RIMON

The TPS25985x 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.

GUID-20220514-SS0I-L1GD-6XHP-SSTGKF7GV53Z-low.gifFigure 8-6 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 individual device load current at all times and can also be used as an analog load current monitor for each individual 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.