SLVSH38 November   2023 TPS61377

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 ESD Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 VCC Power Supply
      2. 7.3.2 Enable and Programmable UVLO
      3. 7.3.3 Soft Start
      4. 7.3.4 Switching Frequency
      5. 7.3.5 Programmable Inductor Peak Current Limit
      6. 7.3.6 Shut Down
      7. 7.3.7 Overvoltage Protection
      8. 7.3.8 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operation
      2. 7.4.2 Forced PWM Mode
      3. 7.4.3 Auto PFM Mode
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Setting Output Voltage
        2. 8.2.2.2 Inductor Selection
        3. 8.2.2.3 Bootstrap Capacitor Selection
        4. 8.2.2.4 Input Capacitor Selection
        5. 8.2.2.5 Output Capacitor Selection
        6. 8.2.2.6 Loop Stability
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
        1. 8.4.2.1 Thermal Considerations
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Third-Party Products Disclaimer
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.2 Enable and Programmable UVLO

The TPS61377 has a dual function enable and UVLO circuit. When the input voltage at the VIN pin is above the input UVLO rising threshold of 2.8 V typical and the EN/UVLO pin is pulled above the rising threshold, the TPS61377 is enabled and starts switching. The EN/UVLO pin has an accurate UVLO voltage threshold to support programmable input under-voltage lockout with hysteresis. A hysteresis current IUVLO_HYS is sourced out of the EN/UVLO pin to provide hysteresis that prevents on/off chattering in the presence of input voltage noise. By using resistor divider as shown in Figure 7-1 , the turn on threshold can be calculated by using Equation 1.

Equation 1. VIN(UVLO_ON)=VUVLO×(1+R1R2)

where

  • VUVLO is the UVLO threshold of 0.813 V at the EN/UVLO pin

The hysteresis between the UVLO turn on threshold and turn off threshold is set by the upper resistor in the EN/UVLO resistor divider and is given by Equation 2

Equation 2. ΔVIN(UVLO)=IUVLO_HYS×R1

where

  • IUVLO is the sourcing current from the EN/UVLO pin when the voltage at the EN/UVLO pin is above VUVLO

GUID-AB7474FB-8EF2-448E-8988-FAC45FBFC7DF-low.svgFigure 7-1 Programmable UVLO with Resistor Divider at EN/UVLO Pin