SLVSHP7 November   2025 TPS548A23

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  D-CAP4 Control
      2. 6.3.2  Internal VCC LDO and Using External Bias On the VCC Pin
        1. 6.3.2.1 Powering the Device From a Single Bus
        2. 6.3.2.2 Powering the Device From a Split-Rail Configuration
      3. 6.3.3  Multifunction Configuration (CFG1-5) Pins
        1. 6.3.3.1 Multifunction Configuration (CFG1-2) Pins (Internal Feedback)
        2. 6.3.3.2 Multifunction Configuration (CFG1-2) Pins (External Feedback)
        3. 6.3.3.3 Multifunction Configuration (CFG3-5) Pins
      4. 6.3.4  Enable
      5. 6.3.5  Soft Start
      6. 6.3.6  Power Good
      7. 6.3.7  Overvoltage and Undervoltage Protection
      8. 6.3.8  Output Voltage Setting (External Feedback Configuration)
      9. 6.3.9  Remote Sense
      10. 6.3.10 Low-side MOSFET Zero-Crossing
      11. 6.3.11 Current Sense and Positive Overcurrent Protection
      12. 6.3.12 Low-side MOSFET Negative Current Limit
      13. 6.3.13 Output Voltage Discharge
      14. 6.3.14 UVLO Protection
      15. 6.3.15 Thermal Shutdown
    4. 6.4 Device Functional Modes
      1. 6.4.1 Auto-Skip (PFM) Eco-mode Light Load Operation
      2. 6.4.2 Forced Continuous-Conduction Mode
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Output Voltage Setting Point
        2. 7.2.2.2 Choose the Switching Frequency
        3. 7.2.2.3 Choose the Inductor
        4. 7.2.2.4 Choose the Output Capacitor
        5. 7.2.2.5 Choose the Input Capacitors (CIN)
        6. 7.2.2.6 VCC Bypass Capacitor
        7. 7.2.2.7 BOOT Capacitor
        8. 7.2.2.8 PG Pullup Resistor
      3. 7.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Documentation Support
      1. 8.1.1 Related Documentation
    2. 8.2 Receiving Notification of Documentation Updates
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

6.3.10 Low-side MOSFET Zero-Crossing

The device uses a zero-crossing (ZC) circuit to perform the zero inductor current detection during skip-mode operation. The ZC threshold is set to a small negative value before the low-side MOSFET is turned off, entering discontinuous conduction mode (DCM) operation. After entering DCM, the ZC threshold hysteresis increases the threshold to a small positive value after entering DCM. As a result, the device delivers better light-load efficiency.

When the load current increases enough such that the device exits DCM, the ZC circuit must detect 16 consecutive cycles of negative inductor current below the ZC threshold before returning to DCM. Only one cycle without ZC detection is required to exit DCM.

When the output is enabled, the ZC circuit is also enabled during the first 32 switching cycles while the device is in soft start. If the device is configured for FCCM, ZC is disabled and the device transitions to FCCM when soft start is complete. See Soft Start for a description on soft-start completion. If there are not at least 32 switching cycles before soft-start is done, such as during start-up with a high output prebias, the ZC is not disabled until the first high-side MOSFET on-time after soft-start done is complete.