SNVSBK9I November   2019  – October 2025 LM63635-Q1

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison Table
  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 Timing Requirements
    7. 6.7 Switching Characteristics
    8. 6.8 System Characteristics
    9. 6.9 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 Sync/Mode Selection
      2. 7.3.2 Output Voltage Selection
      3. 7.3.3 Switching Frequency Selection
        1. 7.3.3.1 Spread Spectrum Option
      4. 7.3.4 Enable and Start-Up
      5. 7.3.5 RESET Flag Output
      6. 7.3.6 Undervoltage Lockout and Thermal Shutdown and Output Discharge
    4. 7.4 Device Functional Modes
      1. 7.4.1 Overview
      2. 7.4.2 Light Load Operation
        1. 7.4.2.1 Sync/FPWM Operation
      3. 7.4.3 Dropout Operation
      4. 7.4.4 Minimum On-time Operation
      5. 7.4.5 Current Limit and Short-Circuit 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  Choosing the Switching Frequency
        2. 8.2.2.2  Setting the Output Voltage
          1. 8.2.2.2.1 CFF Selection
        3. 8.2.2.3  Inductor Selection
        4. 8.2.2.4  Output Capacitor Selection
        5. 8.2.2.5  Input Capacitor Selection
        6. 8.2.2.6  CBOOT
        7. 8.2.2.7  VCC
        8. 8.2.2.8  External UVLO
        9. 8.2.2.9  Maximum Ambient Temperature
        10. 8.2.2.10 Full Feature Design Example
      3. 8.2.3 Application Curves
      4. 8.2.4 EMI Performance Curves
    3. 8.3 Best Design Practices
    4. 8.4 Power Supply Recommendations
    5. 8.5 Layout
      1. 8.5.1 Layout Guidelines
        1. 8.5.1.1 Ground and Thermal Considerations
      2. 8.5.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Device Support
      1. 9.1.1 Device Nomenclature
    2. 9.2 Documentation Support
      1. 9.2.1 Related Documentation
    3. 9.3 Receiving Notification of Documentation Updates
    4. 9.4 Support Resources
    5. 9.5 Trademarks
    6. 9.6 Electrostatic Discharge Caution
    7. 9.7 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

6.4 Thermal Information

THERMAL METRIC (1) LM63635-Q1 LM63635-Q1 UNIT
DRR0012 (WSON) HTSSOP (PWP)
12 PINS 16 PINS
RθJA Junction-to-ambient thermal resistance (2) 47.4 43.1 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 44.6 35.4 °C/W
RθJB Junction-to-board thermal resistance 20.7 18.5 °C/W
ΨJT Junction-to-top characterization parameter 0.7 0.9 °C/W
ΨJB Junction-to-board characterization parameter 20.7 18.5 °C/W
RθJC(bot) Junction-to-case (bottom) thermal resistance 6.3 4.5 °C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application note.
(2) The value of RθJA given in this table is only valid for comparison with other packages and can not be used for design purposes. These values were calculated in accordance with JESD 51-7, and simulated on a 4-layer JEDEC board. The values do not represent the performance obtained in an actual application. For design information please see the Maximum Ambient Temperature section.