SNVS553C January   2008  – November 2016 LM3407

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
  6. 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 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Floating Buck Switching Converter
      2. 7.3.2 Pulse Level Modulation (PLM)
      3. 7.3.3 Internal VCC Regulator
      4. 7.3.4 Clock Generator
      5. 7.3.5 PWM Dimming of LED String
      6. 7.3.6 Input Under-Voltage Lock-Out (UVLO)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Low-Power Shutdown Mode
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Switching Frequency Selection
      2. 8.1.2 LED Current Setting
      3. 8.1.3 Input and Output Capacitors
      4. 8.1.4 Selection of Inductor
      5. 8.1.5 Free-Wheeling Diode
    2. 8.2 Typical Applications
      1. 8.2.1 LM3407 Design Example
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Calculate RISNS
          2. 8.2.1.2.2 Calculate RFS
          3. 8.2.1.2.3 Choose L
          4. 8.2.1.2.4 Choose CIN and CVCC
        3. 8.2.1.3 Application Curve
      2. 8.2.2 Typical Application for Driving 6 LEDs
      3. 8.2.3 Typical Application for Driving 1 LED
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Receiving Notification of Documentation Updates
    3. 11.3 Community Resources
    4. 11.4 Trademarks
    5. 11.5 Electrostatic Discharge Caution
    6. 11.6 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

1 Features

  • Input Operating Range 4.5 V to 30 V
  • Output Voltage Range: 0.1 VIN to 0.9 VIN
  • Accurate Constant Current Output
  • Independent Device Enable (CMOS Compatible) and PWM Dimming Control
  • Converter Switching Frequency Adjustable From 300 kHz to 1 MHz
  • No External Control Loop Compensation Required
  • Supports Ceramic and Low ESR Output Capacitors
  • Input Undervoltage Lockout (UVLO)
  • Thermal Shutdown Protection
  • MSOP-8 PowerPAD Package

2 Applications

  • LED Drivers
  • Constant Current Sources
  • Automotive Lighting
  • General Illumination
  • Industrial Lighting

3 Description

The LM3407 device is a constant current output floating buck switching converter designed to provide constant current to high-power LEDs. The device is ideal for automotive, industrial, and general lighting applications. The LM3407 has an integrated power N-channel MOSFET that makes the application solution compact and simple to implement. An external 1% thick-film resistor allows the converter output voltage to adjust as needed to deliver constant current within 10% accuracy to a serially connected LED string of varying number and type. Converter switching frequency is adjustable from 300 kHz to 1 MHz. The LM3407 features a dimming input to enable LED brightness control by Pulse Width Modulation (PWM). Additionally, a separate enable pin allows for low-power shutdown. An exposed pad MSOP-8 package provides excellent heat dissipation and thermal performance. Input UVLO and output open-circuit protection ensure a robust LED driver solution.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (NOM)
LM3407 MSOP-PowerPAD (8) 3.00 mm × 3.00 mm
  1. For all available packages, see the orderable addendum at the end of the data sheet.

Simplified Application Schematic

LM3407 30046635.png