SNVS974B April   2013  – October 2015 LM3630A

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 I2C-Compatible Timing Requirements (SCL, SDA)
    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 Operation
        1. 7.3.1.1  Control Bank Mapping
        2. 7.3.1.2  PWM Input Polaritiy
        3. 7.3.1.3  HWEN Input
        4. 7.3.1.4  SEL Input
        5. 7.3.1.5  INTN Output
        6. 7.3.1.6  Boost Converter
        7. 7.3.1.7  Boost Switching Frequency Select
        8. 7.3.1.8  Adaptive Headroom
        9. 7.3.1.9  Current Sinks
        10. 7.3.1.10 Current String Biasing
        11. 7.3.1.11 Full-Scale LED Current
        12. 7.3.1.12 Brightness Register
        13. 7.3.1.13 Exponential Mapping
        14. 7.3.1.14 Linear Mapping
      2. 7.3.2 Test Features
        1. 7.3.2.1 Open LED String (LED1 And LED2)
        2. 7.3.2.2 Shorted LED String
        3. 7.3.2.3 Overvoltage Protection (Manufacturing Fault Detection and Shutdown)
      3. 7.3.3 Fault Flags/Protection Features
        1. 7.3.3.1 Overvoltage Protection (Inductive Boost Operation)
        2. 7.3.3.2 Current Limit
        3. 7.3.3.3 Thermal Shutdown
      4. 7.3.4 Initialization Timing
        1. 7.3.4.1 Initialization Timing With HWEN Tied to VIN
        2. 7.3.4.2 Initialization Timing With HWEN Driven by GPIO
        3. 7.3.4.3 Initialization After Software Reset
    4. 7.4 Device Functional Modes
      1. 7.4.1 LED Current Ramping
        1. 7.4.1.1 Start-Up/Shutdown Ramp
        2. 7.4.1.2 Run-Time Ramp
      2. 7.4.2 PWM Operation
        1. 7.4.2.1 PWM Input
        2. 7.4.2.2 PWM Input Frequency
        3. 7.4.2.3 Recommended Settings
        4. 7.4.2.4 Adjustments to PWM Sampler
          1. 7.4.2.4.1 Filter Strength, Register 50h Bits [1:0]
          2. 7.4.2.4.2 Hysteresis 1 Bit, Register 05h, Bit 7
          3. 7.4.2.4.3 Lower Bound Disable, Register 05h, Bit 6
        5. 7.4.2.5 Minimum TON Pulse Width
    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
    6. 7.6 Register Maps
      1. 7.6.1 LM3630A I2C Register Map
      2. 7.6.2 Register Descriptions
  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 Selection
        2. 8.2.2.2 Maximum Power Output
      3. 8.2.3 Application Curves
    3. 8.3 Initialization Setup
      1. 8.3.1 Recommended Initialization Sequence
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Output Capacitor Placement
      2. 10.1.2 Schottky Diode Placement
      3. 10.1.3 Inductor Placement
      4. 10.1.4 Input Capacitor Selection and Placement
    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 LM3630A operates from a 2.3-V to 5.5-V input voltage. The boost switching frequency is programmable at 500 kHz for low switching loss performance or 1 MHz to allow the use of tiny low-profile inductors. This input supply must be well regulated and provide the peak current required by the LED configuration and inductor selected.