SLUSFE0 august   2023 TPSM843B22E

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Revision History
  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  VIN Pins and VIN UVLO
      2. 7.3.2  Internal Bypassing (BP5)
      3. 7.3.3  Enable and Adjustable UVLO
        1. 7.3.3.1 Internal Sequence of Events During Start-up
      4. 7.3.4  Switching Frequency Selection
      5. 7.3.5  Switching Frequency Synchronization to an External Clock
        1. 7.3.5.1 Internal PWM Oscillator Frequency
        2. 7.3.5.2 Loss of Synchronization
        3. 7.3.5.3 Interfacing the SYNC/FSEL Pin
      6. 7.3.6  Remote Sense Amplifier and Adjusting the Output Voltage
      7. 7.3.7  Loop Compensation Guidelines
        1. 7.3.7.1 Output Filter Inductor Tradeoffs
        2. 7.3.7.2 Ramp Capacitor Selection
        3. 7.3.7.3 Output Capacitor Selection
        4. 7.3.7.4 Design Method for Good Transient Response
      8. 7.3.8  Soft Start and Prebiased Output Start-up
      9. 7.3.9  MSEL Pin
      10. 7.3.10 Power Good (PG)
      11. 7.3.11 Output Overload Protection
        1. 7.3.11.1 Positive Inductor Current Protection
        2. 7.3.11.2 Negative Inductor Current Protection
      12. 7.3.12 Output Overvoltage and Undervoltage Protection
      13. 7.3.13 Overtemperature Protection
      14. 7.3.14 Output Voltage Discharge
    4. 7.4 Device Functional Modes
      1. 7.4.1 Forced Continuous-Conduction Mode
      2. 7.4.2 Discontinuous Conduction Mode During Soft Start
      3. 7.4.3 High Side MOSFET and Gate Drive Reduction
  9. 8 Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 1.0-V Output, 1-MHz Application
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1  Switching Frequency
          2. 8.2.1.2.2  Output Inductor Selection
          3. 8.2.1.2.3  Output Capacitor
          4. 8.2.1.2.4  Input Capacitor
          5. 8.2.1.2.5  Adjustable Undervoltage Lockout
          6. 8.2.1.2.6  Output Voltage Resistors Selection
          7. 8.2.1.2.7  Bootstrap Capacitor Selection
          8. 8.2.1.2.8  BP5 Capacitor Selection
          9. 8.2.1.2.9  PG Pullup Resistor
          10. 8.2.1.2.10 Current Limit Selection
          11. 8.2.1.2.11 Soft-Start Time Selection
          12. 8.2.1.2.12 Ramp Selection and Control Loop Stability
          13. 8.2.1.2.13 MSEL Pin
        3. 8.2.1.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
      3. 8.4.3 Thermal Performance
  10. 9 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
8.2.1.2.11 Soft-Start Time Selection

The MSEL pin is used to select between four different soft-start times, which is useful if a load has specific timing requirements for the output voltage of the regulator. A longer soft-start time is also useful if the output capacitance is very large and requires large amounts of current to quickly charge the output capacitors to the output voltage level. The large currents necessary to charge the capacitor can reach the current limit or cause the input voltage rail to sag due excessive current draw from the input power supply. Limiting the output voltage slew rate solves both of these problems. The example design has the soft-start time set to 2.0 ms.