SLUSFD2B September   2023  – March 2024 TPSM861252 , TPSM861253 , TPSM861257

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Family Devices
  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 PWM Operation and D-CAP3™ Control Mode
      2. 7.3.2 Eco-mode Control
      3. 7.3.3 Soft Start and Prebiased Soft Start
      4. 7.3.4 Overvoltage Protection
      5. 7.3.5 Frequency
      6. 7.3.6 Large Duty Operation
      7. 7.3.7 Current Protection and Undervoltage Protection
      8. 7.3.8 Undervoltage Lockout (UVLO) Protection
      9. 7.3.9 Thermal Shutdown
    4. 7.4 Device Functional Modes
      1. 7.4.1 Eco-mode Operation
      2. 7.4.2 FCCM Mode Operation
  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 Custom Design with WEBENCH® Tools
        2. 8.2.2.2 Output Voltage Resistors Selection
        3. 8.2.2.3 Output Filter Selection
        4. 8.2.2.4 Input Capacitor Selection
        5. 8.2.2.5 Enable Circuit
      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. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Development Support
        1. 9.1.1.1 Custom Design with WEBENCH® Tools
    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

8.2.2.3 Output Filter Selection

TPSM86125x integrates a 2.2uH inductor. TI suggests to use the following output cap to make the loop stable. For TPSM861252 and TPSM861257, TI suggests CFF range to use 10pF to 100pF.

Table 8-2 Recommended Component Values
Output Voltage (V)RFBT (kΩ)RFBB (kΩ)Minimum COUT (μF)Typical COUT (μF)Maximum COUT (μF)CFF (pF)
0.83.310.0102288—
1.057.510.0102288—
2.595.030.010228822
3.3135.030.0222210022
5220.030.0222210022
10470.030.0224410010

The capacitor value and ESR determines the amount of output voltage ripple. The TPSM861253 are intended for use with ceramic or other low-ESR capacitors. Use Equation 3 to determine the required RMS current rating for the output capacitor.

Equation 3. ILO(RMS)=IO2+112×IP-P2

For this design, one MuRata GRM21BR61A226ME44L 22µF output capacitor is used. The typical ESR is 2mΩ.