SNVS509F April   2007  – November 2023 LM25116

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 Switching Characteristics
    7. 5.7 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 High-Voltage Start-Up Regulator
      2. 6.3.2 Enable
      3. 6.3.3 UVLO
      4. 6.3.4 Oscillator and Sync Capability
      5. 6.3.5 Error Amplifier and PWM Comparator
      6. 6.3.6 Ramp Generator
      7. 6.3.7 Current Limit
      8. 6.3.8 HO Output
      9. 6.3.9 Thermal Protection
    4. 6.4 Device Functional Modes
      1. 6.4.1 Soft Start and Diode Emulation
  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  Timing Resistor
        2. 7.2.2.2  Output Inductor
        3. 7.2.2.3  Current Sense Resistor
        4. 7.2.2.4  Ramp Capacitor
        5. 7.2.2.5  Output Capacitors
        6. 7.2.2.6  Input Capacitors
        7. 7.2.2.7  VCC Capacitor
        8. 7.2.2.8  Bootstrap Capacitor
        9. 7.2.2.9  Soft Start Capacitor
        10. 7.2.2.10 Output Voltage Divider
        11. 7.2.2.11 UVLO Divider
        12. 7.2.2.12 MOSFETs
        13. 7.2.2.13 MOSFET Snubber
        14. 7.2.2.14 Error Amplifier Compensation
        15. 7.2.2.15 Comprehensive Equations
          1. 7.2.2.15.1 Current Sense Resistor and Ramp Capacitor
          2. 7.2.2.15.2 Modulator Transfer Function
          3. 7.2.2.15.3 Error Amplifier Transfer Function
      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 Receiving Notification of Documentation Updates
    2. 8.2 Support Resources
    3. 8.3 Trademarks
    4. 8.4 Electrostatic Discharge Caution
    5. 8.5 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

7.2.2.7 VCC Capacitor

The primary purpose of the VCC capacitor (CVCC) is to supply the peak transient currents of the LO driver and bootstrap diode (D1) as well as provide stability for the VCC regulator. These current peaks can be several amperes. The recommended value of CVCC must be no smaller than 0.47 µF, and must be a good quality, low ESR, ceramic capacitor placed at the pins of the IC to minimize potentially damaging voltage transients caused by trace inductance. A value of 1 µF was selected for this design.