SLVSGP3A May   2023  – February 2024 TPS54KB20

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  Internal VCC LDO and Using External Bias On the VCC Pin
      2. 6.3.2  Enable
      3. 6.3.3  Adjustable Soft Start
      4. 6.3.4  Power Good
      5. 6.3.5  Output Voltage Setting
      6. 6.3.6  Remote Sense
      7. 6.3.7  D-CAP4 Control
      8. 6.3.8  Multifunction Select (MSEL) Pin
      9. 6.3.9  Low-side MOSFET Zero-Crossing
      10. 6.3.10 Current Sense and Positive Overcurrent Protection
      11. 6.3.11 Low-side MOSFET Negative Current Limit
      12. 6.3.12 Overvoltage and Undervoltage Protection
      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 Eco-mode Light Load Operation
      2. 6.4.2 Forced Continuous-Conduction Mode
      3. 6.4.3 Powering the Device From a Single Bus
      4. 6.4.4 Powering the Device From a Split-rail Configuration
  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 and the Operation Mode
        3. 7.2.2.3  Choose the Inductor
        4. 7.2.2.4  Set the Current Limit (ILIM)
        5. 7.2.2.5  Choose the Output Capacitor
        6. 7.2.2.6  RAMP Selection
        7. 7.2.2.7  Choose the Input Capacitors (CIN)
        8. 7.2.2.8  Soft-Start Capacitor (SS Pin)
        9. 7.2.2.9  EN Pin Resistor Divider
        10. 7.2.2.10 VCC Bypass Capacitor
        11. 7.2.2.11 BOOT Capacitor
        12. 7.2.2.12 RC Snubber
        13. 7.2.2.13 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

Package Options

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

7.2.2.1 Output Voltage Setting Point

To program the output voltage, use the voltage-divider resistors, RFB_T and RFB_B, as shown in Figure 7-1. Connect RFB_T between the FB pin and the output, and connect RFB_B between the FB pin and GOSNS. The recommended value for RFB_B value is 10 kΩ, but it can be set to any value between 1 kΩ to 15 kΩ. For this example, RFB_B was set to 3.01 kΩ. To determine the value of RFB_T for the TPS54KB20, use Equation 8.

Equation 8. R FB_T = R FB_B × V O U T - V R E F V R E F = 3.01   k Ω × 3.3   V - 0.9   V 0.9   V = 8   k Ω