SLVSE48C january   2018  – may 2023 TPS65268-Q1

PRODUCTION DATA  

  1.   1
  2. Features
  3. Applications
  4. Description
  5. Revision History
  6. Pin Configuration and Functions
  7. 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 Timing Requirements
    7. 6.7 Typical Characteristics
  8. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Adjusting the Output Voltage
      2. 7.3.2  Enable and Adjusting UVLO
      3. 7.3.3  Soft-Start Time
      4. 7.3.4  Power-Up Sequencing
      5. 7.3.5  V7V Low-Dropout Regulator and Bootstrap
      6. 7.3.6  Out-of-Phase Operation
      7. 7.3.7  Output Overvoltage Protection (OVP)
      8. 7.3.8  Slope Compensation
      9. 7.3.9  Overcurrent Protection
        1. 7.3.9.1 High-Side MOSFET Overcurrent Protection
        2. 7.3.9.2 Low-Side MOSFET Overcurrent Protection
      10. 7.3.10 Power Good
        1. 7.3.10.1 Adjustable Switching Frequency
      11. 7.3.11 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Normal Operation
      2. 7.4.2 Standby Operation
  9. 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 Output Inductor Selection
        2. 8.2.2.2 Output Capacitor Selection
        3. 8.2.2.3 Input Capacitor Selection
        4. 8.2.2.4 Loop Compensation
      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
  10. Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  11. 10Mechanical, Packaging, and Orderable Information

Package Options

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

Adjusting the Output Voltage

The output voltage of each buck converter is set with a resistor divider from the output of the buck converter to the FB pin as shown in Figure 7-1. TI recommends using1% tolerance or better resistors. Use Equation 1 to calculate the value of R2.

GUID-6E079E96-3231-4767-AEB5-0F1B436587F8-low.gifFigure 7-1 Voltage Divider Circuit
Equation 1. GUID-B28F6A8C-1464-49B9-B58D-3031C1EE4804-low.gif

To improve efficiency at light loads, consider using larger value resistors. If the values are too high, the regulator is more sensitive to noise. Table 7-1 lists the recommended resistor values.

Table 7-1 Output Resistor Divider Selection
OUTPUT VOLTAGE
(V)
R1
(kΩ)
R2
(kΩ)
11015
1.21010
1.51510
1.82010
2.531.610
3.345.310
3.322.64.99
573.210
536.54.99