SNVS594G December   2008  – April 2016 LM3555

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 Control Interface Timing Requirements
    7. 6.7 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  Synchronous Boost Converter
      2. 7.3.2  High-Side Current Source
      3. 7.3.3  I2C/EN Pin
      4. 7.3.4  SDA/EN2 and SCL/EN1 Pins
      5. 7.3.5  STROBE Pin
      6. 7.3.6  TORCH Pin
      7. 7.3.7  Indicator LED Pin (IND)
      8. 7.3.8  Internal Diode Detection
      9. 7.3.9  Fault Protections
        1. 7.3.9.1 Output Overvoltage Protection (OVP)
        2. 7.3.9.2 Output and LED Short-Circuit Protection (SCP)
        3. 7.3.9.3 Overtemperature Protection (OTP)
        4. 7.3.9.4 Flash Timeout (FTP)
        5. 7.3.9.5 Indicator Fault (IF)
        6. 7.3.9.6 Broken Inductor Fault (IP)
      10. 7.3.10 Undervoltage Lockout (UVLO)
      11. 7.3.11 Power-On Reset (POR)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Single LED Operation
      2. 7.4.2 Dual LED Operation
      3. 7.4.3 Torch or Assist (Continuous Current) Operation
      4. 7.4.4 Flash (Pulsed Current) Operation
      5. 7.4.5 Indicator Operation
      6. 7.4.6 Simple Control State Diagram
    5. 7.5 Programming
      1. 7.5.1 I2C-Compatible Interface
        1. 7.5.1.1 Data Validity
        2. 7.5.1.2 Start and Stop Conditions
        3. 7.5.1.3 Transferring Data
        4. 7.5.1.4 I2C-Compatible Chip Address
    6. 7.6 Register Maps
      1. 7.6.1 Internal Registers of LM3555
      2. 7.6.2 Register Definitions
  8. 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 Inductor Current Limit
        2. 8.2.2.2 Inductor Selection
        3. 8.2.2.3 Capacitor Selection
      3. 8.2.3 Application Curves
  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 Device Support
      1. 11.1.1 Third-Party Products Disclaimer
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    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

9 Power Supply Recommendations

The LM3555 is designed to operate from an input supply range of 2.5 V to 5.5 V. This input supply must be well regulated and provide the peak current required by the LED configuration and inductor selected.