SBVS477A May   2025  – July 2025 TPS7B4259-Q1

PRODUCTION DATA  

  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 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 Tracker Output Voltage (VOUT)
        1. 6.3.1.1 Output Voltage Equal to Reference Voltage
        2. 6.3.1.2 Output Voltage Less Than the Reference Voltage
      2. 6.3.2 Reverse Current Protection
      3. 6.3.3 Power Good
      4. 6.3.4 Undervoltage Lockout
      5. 6.3.5 Thermal Protection
      6. 6.3.6 Current Limit
      7. 6.3.7 Output Short to Battery
    4. 6.4 Device Functional Modes
      1. 6.4.1 Normal Operation
      2. 6.4.2 Dropout Operation
      3. 6.4.3 Operation With VIN < 3.3V
      4. 6.4.4 Disable With ADJ and EN Controls
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Dropout Voltage
      2. 7.1.2 Reverse Current
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Input and Output Capacitor Selection
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
        1. 7.4.1.1 Package Mounting
        2. 7.4.1.2 Board Layout Recommendations to Improve PSRR and Noise Performance
        3. 7.4.1.3 Power Dissipation and Thermal Considerations
        4. 7.4.1.4 Thermal Performance Versus Copper Area
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Device Nomenclature
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

6.3.6 Current Limit

The device has an internal current limit circuit that protects the device during overcurrent or shorting conditions. The current-limit circuit, as shown in Figure 6-3, is a brick-wall scheme. When the device is in current limit, the device sources ICL and the output voltage is not regulated. In this scenario, the output voltage depends on the load impedance.

TPS7B4259-Q1 Brick-Wall Current-Limit SchemeFigure 6-3 Brick-Wall Current-Limit Scheme

During current-limit events, the potential for high power dissipation exists because of the elevated current level and the increased input-to-output differential voltage (VIN – VOUT). If the heat dissipation is substantial, the device enters thermal shutdown. If the current-limit condition is not removed when the device turns back on after cooling, the device enters thermal shutdown again. This cycle continues until the current-limit condition is removed. The device survives this fault, but repeatedly operating in this mode degrades long-term reliability.