SNVS411D January   2006  – December 2025 LM25005

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 Resistance Characteristics
    5. 5.5 Electrical Characteristics
    6. 5.6 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 Oscillator and Sync Capability
      3. 6.3.3 Error Amplifier and PWM Comparator
      4. 6.3.4 RAMP Generator
      5. 6.3.5 Soft-Start
      6. 6.3.6 Current Limit
    4. 6.4 Device Functional Modes
      1. 6.4.1 Shutdown / Standby
      2. 6.4.2 Boost Pin
      3. 6.4.3 Thermal Protection
  8. 7 Application and Implementation
    1. 7.1 Application Information Disclaimer
    2. 7.2 Application Information
      1. 7.2.1 Bias Power Dissipation Reduction
    3. 7.3 Typical Application
      1. 7.3.1 Design Requirements
      2. 7.3.2 Detailed Design Procedure
        1. 7.3.2.1 Custom Design With WEBENCH® Tools
        2. 7.3.2.2 External Components
          1. 7.3.2.2.1  R3 (RT)
          2. 7.3.2.2.2  L1
          3. 7.3.2.2.3  C3 (CRAMP)
          4. 7.3.2.2.4  C9, C10
          5. 7.3.2.2.5  D1
          6. 7.3.2.2.6  C1, C2
          7. 7.3.2.2.7  C8
          8. 7.3.2.2.8  C7
          9. 7.3.2.2.9  C4
          10. 7.3.2.2.10 R5, R6
          11. 7.3.2.2.11 R1, R2, C12
          12. 7.3.2.2.12 R7, C11
          13. 7.3.2.2.13 R4, C5, C6
      3. 7.3.3 Application Curves
    4. 7.4 Power Supply Recommendations
    5. 7.5 Layout
      1. 7.5.1 Layout Guidelines
      2. 7.5.2 Layout Example
      3. 7.5.3 Power Dissipation
      4. 7.5.4 Thermal Design
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Third-Party Products Disclaimer
      2. 8.1.2 Development Support
        1. 8.1.2.1 Custom Design With WEBENCH® Tools
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Export Control Notice
    8. 8.8 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
7.3.2.2.9 C4

The capacitor at the SS pin determines the soft-start time, for example, the time for the reference voltage and the output voltage to reach the final regulated value. The time is determined using:

Equation 11. t s s = C 4 × 1.225 V 10 μ A

For this application, a C4 value of 0.01µF is used as this value corresponds to a soft-start time of 1ms.