SLVSFC9B October   2020  – March 2022 TPS25947

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  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 Timing Requirements
    7. 7.7 Switching Characteristics
      1.      15
    8. 7.8 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  Input Reverse Polarity Protection
      2. 8.3.2  Undervoltage Lockout (UVLO and UVP)
      3. 8.3.3  Overvoltage Lockout (OVLO)
      4. 8.3.4  Overvoltage Clamp (OVC)
      5. 8.3.5  Inrush Current, Overcurrent, and Short Circuit Protection
        1. 8.3.5.1 Slew Rate (dVdt) and Inrush Current Control
        2. 8.3.5.2 Circuit-Breaker
        3. 8.3.5.3 Active Current Limiting
        4. 8.3.5.4 Short-Circuit Protection
      6. 8.3.6  Analog Load Current Monitor
      7. 8.3.7  Reverse Current Protection
      8. 8.3.8  Overtemperature Protection (OTP)
      9. 8.3.9  Fault Response and Indication (FLT)
      10. 8.3.10 Auxiliary Channel Control (AUXOFF)
      11. 8.3.11 Power Good Indication (PG)
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Single Device, Self-Controlled
    3. 9.3 Typical Application
      1. 9.3.1 Design Requirements
      2. 9.3.2 Detailed Design Procedure
        1. 9.3.2.1 Device Selection
        2. 9.3.2.2 Setting Undervoltage and Overvoltage Thresholds
        3. 9.3.2.3 Setting Output Voltage Rise Time (tR)
        4. 9.3.2.4 Setting Power Good Assertion Threshold
        5. 9.3.2.5 Setting Overcurrent Threshold (ILIM)
        6. 9.3.2.6 Setting Overcurrent Blanking Interval (tITIMER)
      3. 9.3.3 Application Curves
    4. 9.4 Active ORing
    5. 9.5 Priority Power MUXing
    6. 9.6 USB PD Port Protection
    7. 9.7 Parallel Operation
  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

8.1 Overview

The TPS25947xx is an eFuse with integrated power path that is used to ensure safe power delivery in a system. The device starts its operation by monitoring the IN bus. When the input supply voltage (VIN) exceeds the Undervoltage Protection threshold (VUVP), the device samples the EN/UVLO pin. A high level (> VUVLO) on this pin enables the internal power path (BFET+HFET) to start conducting and allow current to flow from IN to OUT. When EN/UVLO is held low (< VUVLO), the internal power path is turned off. In case of reverse voltages appearing at the input, the power path remains OFF thereby protecting the output load.

After a successful start-up sequence, the device now actively monitors its load current and input voltage, and controls the internal HFET to ensure that the user adjustable overcurrent limit threshold (ILIM) is not exceeded and overvoltage spikes are either safely clamped to the selected threshold voltage (VOVC) or cut-off after they cross the user adjustable overvoltage lockout threshold (VOVLO). The device also provides fast protection against severe overcurrent during short-circuit events. This keeps the system safe from harmful levels of voltage and current. At the same time, a user adjustable overcurrent blanking timer allows the system to pass moderate transient peaks in the load current profile without tripping the eFuse. This ensures a robust protection solution against real faults which is also immune to transients, thereby ensuring maximum system uptime.

The device has integrated reverse current blocking FET (BFET) which operates like an ideal diode. The BFET is linearly regulated to maintain a small constant forward drop (VFWD) in forward conduction mode and turned off completely to block reverse current if output voltage exceeds the input voltage.

The device also has a built-in thermal sensor based shutdown mechanism to protect itself in case the device temperature (TJ) exceeds the recommended operating conditions.