SNVS602L March   2009  – June 2016 LM3409 , LM3409-Q1 , LM3409HV , LM3409HV-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Buck Current Regulators
      2. 8.3.2 Controlled Off-Time (COFT) Architecture
        1. 8.3.2.1 Adjustable Peak Current Control
        2. 8.3.2.2 Controlled Off-Time
      3. 8.3.3 Average LED Current
      4. 8.3.4 Inductor Current Ripple
      5. 8.3.5 Switching Frequency
      6. 8.3.6 PWM Dimming Using the EN Pin
      7. 8.3.7 High Voltage Negative BIAS Regulator
      8. 8.3.8 External Parallel FET PWM Dimming
    4. 8.4 Device Functional Modes
      1. 8.4.1 Low-Power Shutdown
      2. 8.4.2 Thermal Shutdown
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Input Undervoltage Lockout (UVLO)
      2. 9.1.2 Operation Near Dropout
      3. 9.1.3 LED Ripple Current
      4. 9.1.4 Buck Converters without Output Capacitors
      5. 9.1.5 Buck Converters With Output Capacitors
      6. 9.1.6 Output Overvoltage Protection
      7. 9.1.7 Input Capacitors
      8. 9.1.8 P-Channel MOSFET (PFET)
      9. 9.1.9 Re-Circulating Diode
    2. 9.2 Typical Applications
      1. 9.2.1 EN PIN PWM Dimming Application for 10 LEDs
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
          1. 9.2.1.2.1  Nominal Switching Frequency
          2. 9.2.1.2.2  Inductor Ripple Current
          3. 9.2.1.2.3  Average LED Current
          4. 9.2.1.2.4  Output Capacitance
          5. 9.2.1.2.5  Input Capacitance
          6. 9.2.1.2.6  PFET
          7. 9.2.1.2.7  Diode
          8. 9.2.1.2.8  Input UVLO
          9. 9.2.1.2.9  IADJ Connection Method
          10. 9.2.1.2.10 PWM Dimming Method
        3. 9.2.1.3 Application Curve
      2. 9.2.2 Analog Dimming Application for 4 LEDs
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
          1. 9.2.2.2.1  Nominal Switching Frequency
          2. 9.2.2.2.2  Inductor Ripple Current
          3. 9.2.2.2.3  Average LED Current
          4. 9.2.2.2.4  Output Capacitance
          5. 9.2.2.2.5  Input Capacitance
          6. 9.2.2.2.6  PFET
          7. 9.2.2.2.7  Diode
          8. 9.2.2.2.8  Input UVLO
          9. 9.2.2.2.9  IADJ Connection Method
          10. 9.2.2.2.10 PWM Dimming Method
        3. 9.2.2.3 Application Curve
      3. 9.2.3 LM3409 Buck Converter Application
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
          1. 9.2.3.2.1  Nominal Switching Frequency
          2. 9.2.3.2.2  Inductor Ripple Current
          3. 9.2.3.2.3  Average LED Current
          4. 9.2.3.2.4  Output Capacitance
          5. 9.2.3.2.5  Input Capacitance
          6. 9.2.3.2.6  PFET
          7. 9.2.3.2.7  Diode
          8. 9.2.3.2.8  Input UVLO
          9. 9.2.3.2.9  IADJ Connection Method
          10. 9.2.3.2.10 PWM Dimming Method
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Third-Party Products Disclaimer
    2. 12.2 Related Links
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

13 Mechanical, Packaging, and Orderable Information

The following pages include mechanical, packaging, and orderable information. This information is the most current data available for the designated devices. This data is subject to change without notice and revision of this document. For browser-based versions of this data sheet, refer to the left-hand navigation.