SLVSGA8B May   2021  – April 2022 TPS25946

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 Undervoltage Lockout (UVLO and UVP)
      2. 8.3.2 Overvoltage Lockout (OVLO)
      3. 8.3.3 Inrush Current, Overcurrent, and Short-Circuit Protection
        1. 8.3.3.1 Slew Rate (dVdt) and Inrush Current Control
        2. 8.3.3.2 Active Current Limiting
        3. 8.3.3.3 Short-Circuit Protection
      4. 8.3.4 Analog Load Current Monitor
      5. 8.3.5 Reverse Current Protection
      6. 8.3.6 Overtemperature Protection (OTP)
      7. 8.3.7 Fault Response and Indication (FLT)
      8. 8.3.8 Power Good Indication (PG)
      9. 8.3.9 Input Supply Good Indication (SPLYGD)
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Single Device, Self-Controlled
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Device Selection
        2. 9.2.2.2 Setting Overvoltage Threshold
        3. 9.2.2.3 Setting Output Voltage Rise Time (tR)
        4. 9.2.2.4 Setting Power Good Assertion Threshold
        5. 9.2.2.5 Setting Overcurrent Threshold (ILIM)
        6. 9.2.2.6 Setting Overcurrent Blanking Interval (tITIMER)
        7. 9.2.2.7 Selecting External Bias Resistor (R5)
        8. 9.2.2.8 Selecting External Diode (D1)
      3. 9.2.3 Application Curve
  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

8.3.3.1 Slew Rate (dVdt) and Inrush Current Control

During hot-plug events or while trying to charge a large output capacitance at start-up, there can be a large inrush current. If the inrush current is not managed properly, it can damage the input connectors and/or cause the system power supply to droop leading to unexpected restarts elsewhere in the system. The inrush current during turn-on is directly proportional to the load capacitance and rising slew rate. Equation 3 can be used to find the slew rate (SR) required to limit the inrush current (IINRUSH) for a given load capacitance (COUT):

Equation 3. GUID-366627C1-3E80-42C3-A667-82DD9D3FE348-low.gif

A capacitor can be connected to the dVdt pin to control the rising slew rate and lower the inrush current during turn-on. The required CdVdt capacitance to produce a given slew rate can be calculated using Equation 4.

Equation 4. GUID-C9170726-E84F-4C84-A0E1-FB74E1635892-low.gif

The fastest output slew rate is achieved by leaving the dVdt pin open.

Note:

For CdVdt > 10 nF, TI recommends to add a 100-Ω resistor in series with the capacitor on the dVdt pin.