SLVSHO1 March   2025 TPS1689

ADVANCE INFORMATION  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  Recommended Operating Conditions
    4. 5.4  Thermal Information
    5. 5.5  Electrical Characteristics
    6. 5.6  PMBus and GPIO DC Characteristics
    7. 5.7  Telemetry
    8. 5.8  Logic Interface
    9. 5.9  Timing Requirements
    10. 5.10 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1  Undervoltage Protection
      2. 6.3.2  Insertion Delay
      3. 6.3.3  Overvoltage Protection
      4. 6.3.4  Inrush Current, Overcurrent, and Short-Circuit Protection
        1. 6.3.4.1 Slew rate (dVdt) and Inrush Current Control
          1. 6.3.4.1.1 Start-Up Timeout
        2. 6.3.4.2 Steady-State Overcurrent Protection (Circuit-Breaker)
        3. 6.3.4.3 Active Current Limiting During Start-Up
        4. 6.3.4.4 Short-Circuit Protection
      5. 6.3.5  Analog Load Current Monitor (IMON)
      6. 6.3.6  Overtemperature Protection
      7. 6.3.7  Analog Junction Temperature Monitor (TEMP)
      8. 6.3.8  FET Health Monitoring
      9. 6.3.9  Single Point Failure Mitigation
        1. 6.3.9.1 IMON Pin Single Point Failure
        2. 6.3.9.2 IREF Pin Single Point Failure
      10. 6.3.10 General Purpose Digital Input/Output Pins
        1. 6.3.10.1 Fault Response and Indication (FLT)
        2. 6.3.10.2 Power Good Indication (PG)
        3. 6.3.10.3 Parallel Device Synchronization (SWEN)
      11. 6.3.11 Stacking Multiple eFuses for Unlimited Scalability
        1. 6.3.11.1 Current Balancing During Start-Up
      12. 6.3.12 Quick Output Discharge(QOD)
      13. 6.3.13 Write Protect Feature(WP#)
      14. 6.3.14 PMBus® Digital Interface
        1. 6.3.14.1  PMBus® Device Addressing
        2. 6.3.14.2  SMBus Protocol
        3. 6.3.14.3  SMBus™ Message Formats
        4. 6.3.14.4  Packet Error Checking
        5. 6.3.14.5  Group Commands
        6. 6.3.14.6  SMBus™ Alert Response Address (ARA)
        7. 6.3.14.7  PMBus® Commands
        8. 6.3.14.8  Analog-to-digital Converter
        9. 6.3.14.9  Digital-to-analog Converters
        10. 6.3.14.10 DIRECT format Conversion
        11. 6.3.14.11 Blackbox Fault Recording
    4. 6.4 Device Functional Modes
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Single Device, Standalone Operation
      2. 7.1.2 Single TPS1689 and multiple TPS1685 Devices, Parallel Connection
      3. 7.1.3 Multiple TPS1689 Devices: Parallel Connection With Individual Telemetry
      4. 7.1.4 Multiple Devices, Independent Operation (Multi-zone)
    2. 7.2 Typical Application: 54-V, 2-kW Power Path Protection with PMBus® Interface in Datacenter Servers
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
      3. 7.2.3 Application Performance Plots
    3. 7.3 Power Supply Recommendations
      1. 7.3.1 Transient Protection
      2. 7.3.2 Output Short-Circuit Measurements
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Application Limitation and Errata
  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
    1. 11.1 Mechanical Data

Package Options

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

6.3.5 Analog Load Current Monitor (IMON)

The TPS1689 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 eFuse devices (TPS1689 or TPS1685x) 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 8.

Equation 8. IOUT=VIMONGIMON×RIMON

The TPS1689 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.

TPS1689 Analog Load Current Monitor ResponseFigure 6-6 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. TI recommends adding a 22 pF capacitor from IMON pin to GND for noise filtering purposes.

  4. Care must be taken to minimize parasitic capacitance on the ILIM pin to avoid any impact on the overcurrent and short-circuit protection timing during start-up.