SLVSFC9C October   2020  – May 2026 TPS25947

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 Timing Requirements
    7. 6.7 Switching Characteristics
    8. 6.8 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  Input Reverse Polarity Protection
      2. 7.3.2  Undervoltage Lockout (UVLO and UVP)
      3. 7.3.3  Overvoltage Lockout (OVLO)
      4. 7.3.4  Overvoltage Clamp (OVC)
      5. 7.3.5  Inrush Current, Overcurrent, and Short Circuit Protection
        1. 7.3.5.1 Slew Rate (dVdt) and Inrush Current Control
        2. 7.3.5.2 Circuit-Breaker
        3. 7.3.5.3 Active Current Limiting
        4. 7.3.5.4 Short-Circuit Protection
      6. 7.3.6  Analog Load Current Monitor
      7. 7.3.7  Reverse Current Protection
      8. 7.3.8  Overtemperature Protection (OTP)
      9. 7.3.9  Fault Response and Indication (FLT)
      10. 7.3.10 Auxiliary Channel Control (AUXOFF)
      11. 7.3.11 Power Good Indication (PG)
    4. 7.4 Device Functional Modes
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Single Device, Self-Controlled
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Device Selection
        2. 8.2.2.2 Setting Undervoltage and Overvoltage Thresholds
        3. 8.2.2.3 Setting Output Voltage Rise Time (tR)
        4. 8.2.2.4 Setting Power Good Assertion Threshold
        5. 8.2.2.5 Setting Overcurrent Threshold (ILIM)
        6. 8.2.2.6 Setting Overcurrent Blanking Interval (tITIMER)
      3. 8.2.3 Application Curves
      4. 8.2.4 Active ORing
      5. 8.2.5 Priority Power MUXing
      6. 8.2.6 USB PD Port Protection
      7. 8.2.7 Parallel Operation
    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

7.3.6 Analog Load Current Monitor

The device allows the system to accurately monitor the output load current by providing an analog current sense output on the ILM pin which is proportional to the current through the FET. The user can sense the voltage (VILM) across the RILM to get a measure of the output load current.

Equation 9. I O U T A = V I L M μ V R I L M Ω × G I M O N μ A A

The waveform below shows the ILM signal response to a load step at the output.

TPS25947 Analog Load Current Monitor Response
VIN = 12V, COUT = 22μF, RILM = 1150Ω, IOUT varied dynamically from 0A to 3.5A
Figure 7-12 Analog Load Current Monitor Response
Note: The ILM pin is sensitive to capacitive loading. Careful design and layout is needed to establish the parasitic capacitive loading on the ILM pin is < 50pF for stable operation.