SLUSEA4D June   2021  – August 2022 TPS62932 , TPS62933 , TPS62933F , TPS62933O , TPS62933P

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Device Comparison Table
  7. 7 Pin Configuration and Functions
  8. 8 Specifications
    1. 8.1 Absolute Maximum Ratings
    2. 8.2 ESD Ratings
    3. 8.3 Recommended Operating Conditions
    4. 8.4 Thermal Information
    5. 8.5 Electrical Characteristics
    6. 8.6 Typical Characteristics
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1  Fixed Frequency Peak Current Mode
      2. 9.3.2  Pulse Frequency Modulation
      3. 9.3.3  Voltage Reference
      4. 9.3.4  Output Voltage Setting
      5. 9.3.5  Switching Frequency Selection
      6. 9.3.6  Enable and Adjusting Undervoltage Lockout
      7. 9.3.7  External Soft Start and Prebiased Soft Start
      8. 9.3.8  Power Good
      9. 9.3.9  Minimum On Time, Minimum Off Time, and Frequency Foldback
      10. 9.3.10 Frequency Spread Spectrum
      11. 9.3.11 Overvoltage Protection
      12. 9.3.12 Overcurrent and Undervoltage Protection
      13. 9.3.13 Thermal Shutdown
    4. 9.4 Device Functional Modes
      1. 9.4.1 Modes Overview
      2. 9.4.2 Heavy Load Operation
      3. 9.4.3 Light Load Operation
      4. 9.4.4 Out of Audio Operation
      5. 9.4.5 Forced Continuous Conduction Operation
      6. 9.4.6 Dropout Operation
      7. 9.4.7 Minimum On-Time Operation
      8. 9.4.8 Shutdown Mode
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1  Custom Design With WEBENCH® Tools
        2. 10.2.2.2  Output Voltage Resistors Selection
        3. 10.2.2.3  Choosing Switching Frequency
        4. 10.2.2.4  Soft-Start Capacitor Selection
        5. 10.2.2.5  Bootstrap Capacitor Selection
        6. 10.2.2.6  Undervoltage Lockout Setpoint
        7. 10.2.2.7  Output Inductor Selection
        8. 10.2.2.8  Output Capacitor Selection
        9. 10.2.2.9  Input Capacitor Selection
        10. 10.2.2.10 Feedforward Capacitor CFF Selection
        11. 10.2.2.11 Maximum Ambient Temperature
      3. 10.2.3 Application Curves
    3. 10.3 What to Do and What Not to Do
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Device Support
      1. 13.1.1 Third-Party Products Disclaimer
      2. 13.1.2 Development Support
        1. 13.1.2.1 Custom Design With WEBENCH® Tools
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Support Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

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

9.3.4 Output Voltage Setting

A precision 0.8-V reference voltage, VREF, is used to maintain a tightly regulated output voltage over the entire operating temperature range. The output voltage is set by a resistor divider from the output voltage to the FB pin. TI recommends using 1% tolerance resistors with a low temperature coefficient for the FB divider. Select the bottom-side resistor, RFBB, for the desired divider current and use Equation 1 to calculate the top-side resistor, RFBT. Lower RFBB increases the divider current and reduces efficiency at very light load. Larger RFBB makes the FB voltage more susceptible to noise, so larger RFBB values require a more carefully designed feedback path on the PCB. Setting RFBB = 10 kΩ and RFBT in the range of 10 kΩ to 300 kΩ is recommended for most applications.

The tolerance and temperature variation of the resistor dividers affect the output voltage regulation.

GUID-20210110-CA0I-NJ1Q-DHSF-SD4BNBFXBW7R-low.gif Figure 9-2 Output Voltage Setting
Equation 1. GUID-20210110-CA0I-4VDQ-JXFR-1PSJ8RKZKMBW-low.gif

where

  • VREF is the 0.8 V (the internal reference voltage).
  • RFBB is 10 kΩ (recommended).