SLUSFR0A July   2024  – August 2024 TPS51375

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  PWM Operation and D-CAP3™ Control Mode
      2. 6.3.2  Remote Sense
      3. 6.3.3  Body Braking
      4. 6.3.4  5V LDO and BYP Function
      5. 6.3.5  Soft Start
      6. 6.3.6  Large Duty Operation
      7. 6.3.7  Power Good
      8. 6.3.8  Overcurrent Protection and Undervoltage Protection
      9. 6.3.9  Overvoltage Protection
      10. 6.3.10 UVLO Protection
      11. 6.3.11 Output Voltage Discharge
      12. 6.3.12 Standby Operation
      13. 6.3.13 Thermal Shutdown
    4. 6.4 Device Functional Modes
      1. 6.4.1 Advanced Eco-mode Control
  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 Custom Design With WEBENCH® Tools
        2. 7.2.2.2 External Component Selection
          1. 7.2.2.2.1 Remote Sense Amplifier and Adjusting the Output Voltage
          2. 7.2.2.2.2 Inductor Selection
          3. 7.2.2.2.3 Output Capacitor Selection
          4. 7.2.2.2.4 Input Capacitor Selection
          5. 7.2.2.2.5 Bootstrap Capacitor Selection
      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 Device Support
      1. 8.1.1 Development Support
        1. 8.1.1.1 Custom Design With WEBENCH® Tools
    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
    1. 10.1 Tape and Reel Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

6.3.4 5V LDO and BYP Function

The VCC pin is the output of the internal 5V linear regulator that creates the bias for all the internal circuitry and MOSFET gate drivers. The VCC pin must be bypassed with a 2.2µF capacitor. The UVLO circuit monitors the VCC pin voltage and disables the output when VCC falls below the UVLO threshold.

An external voltage that is connected to the BYP pin can override the internal LDO, switching to the external rail after a higher voltage is detected. This action enhances the efficiency of the converter because the quiescent current now runs off this external rail instead of the input power supply. This BYP external voltage must come after VIN voltage on and quit before VIN off.

The devices is integrated with a VCC switchover function which supports connecting the BYP pin to VOUT directly if the VOUT is set to higher than 4.8V. The VCC switchover function is designed to bypass internal 5V LDO with the power from VOUT. The VCC switchover is a seamless behavior of regulator and does not need any additional configuration.

The VCC pin switchover function is asserted when three conditions are present:

  • PGOOD is not pulled low
  • VOUT voltage is higher than 4.8V
  • BYP pin is short to VOUT.

In this switchover condition, one thing occurs: the VCC output is connected to VOUT by internal switchover MOSFET.