SNVSB55H February   2019  – June 2024 LM63615-Q1 , LM63625-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.     Absolute Maximum Ratings
    2. 6.1 ESD Ratings
    3. 6.2 Recommended Operating Conditions
    4. 6.3 Thermal Information
    5. 6.4 Electrical Characteristics
    6. 6.5 Timing Characteristics
    7. 6.6 Switching Characteristics
    8. 6.7 System Characteristics
    9. 6.8 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
      3. 8.2.3 Full Feature Design Example
      4. 8.2.4 Application Curves
      5. 8.2.5 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

Package Options

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

7.3.1 Sync/Mode Selection

The LM636x5-Q1 features selectable operating modes through the SYNC/MODE input. Table 7-1 shows the selection programming. Mode changes can be made on the fly anytime after the device is powered up. TI does not recommend that this input be allowed to float, however, an internal 100 kΩ pulls the input to ground if left floating. The value of this internal resistor and the logic thresholds for this input can be found in the Electrical Characteristics. See Section 7.4 for details of the operating modes.

Table 7-1 Mode Selection Settings
SYNC/MODE INPUTMODE
VCCFPWM
AGNDAUTO
Synchronizing clockFPWM; synchronized to external clock
Float (not recommended)AUTO