SNVS606L June   2009  – December 2014 LM3530

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 I2C Device Options
  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 I2C-Compatible Timing Requirements (SCL, SDA)
    7. 7.7 Simple Interface Timing
    8. 7.8 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  Start-Up
      2. 8.3.2  Light Load Operation
      3. 8.3.3  Ambient Light Sensor
      4. 8.3.4  ALS Operation
      5. 8.3.5  ALS Averaging Time
        1. 8.3.5.1 Averager Operation
      6. 8.3.6  Zone Boundary Settings
      7. 8.3.7  Zone Boundary Trip Points and Hysteresis
      8. 8.3.8  Minimum Zone Boundary Settings
      9. 8.3.9  LED Current Control
      10. 8.3.10 Exponential or Linear Brightness Mapping Modes
      11. 8.3.11 PWM Input Polarity
      12. 8.3.12 I2C-Compatible Current Control Only
      13. 8.3.13 Simple Enable Disable With PWM Current Control
      14. 8.3.14 Ambient Light Current Control
      15. 8.3.15 Ambient Light Current Control + PWM
      16. 8.3.16 Interrupt Output
      17. 8.3.17 Overvoltage Protection
      18. 8.3.18 Hardware Enable
      19. 8.3.19 Thermal Shutdown
    4. 8.4 Device Functional Modes
      1. 8.4.1 Shutdown
      2. 8.4.2 I2C Mode
      3. 8.4.3 PWM + I2C Mode
      4. 8.4.4 ALS Mode
      5. 8.4.5 Simple Enable Mode
    5. 8.5 Programming
      1. 8.5.1 I2C-Compatible Interface
        1. 8.5.1.1 Start and Stop Condition
        2. 8.5.1.2 I2C-Compatible Address
        3. 8.5.1.3 Transferring Data
    6. 8.6 Register Maps
      1. 8.6.1 Register Descriptions
        1. 8.6.1.1 General Configuration Register (GP)
        2. 8.6.1.2 ALS Configuration Register
        3. 8.6.1.3 Brightness Ramp Rate Register
        4. 8.6.1.4 ALS Zone Information Register
        5. 8.6.1.5 ALS Resistor Select Register
        6. 8.6.1.6 Brightness Control Register
        7. 8.6.1.7 Zone Boundary Register
        8. 8.6.1.8 Zone Target Registers
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 LED Current Setting/Maximum LED Current
        2. 9.2.2.2 Maximum Duty Cycle
        3. 9.2.2.3 Peak Current Limit
        4. 9.2.2.4 Output Voltage Limitations
        5. 9.2.2.5 Output Capacitor Selection
        6. 9.2.2.6 Inductor Selection
        7. 9.2.2.7 Diode Selection
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Output Capacitor Placement
      2. 11.1.2 Schottky Diode Placement
      3. 11.1.3 Inductor Placement
      4. 11.1.4 Input Capacitor Selection and Placement
    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 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

1 Features

  • Drives up to 11 LEDs in series
  • 1000:1 Dimming Ratio
  • 90% Efficient
  • Programmable Dual Ambient Light Sensor Inputs with Internal ALS Voltage Setting Resistors
  • I2C Programmable Logarithmic or Linear Brightness Control
  • External PWM Input for Simple Brightness Adjustment
  • True Shutdown Isolation for LEDs and Ambient Light Sensors
  • Internal Soft-Start Limits Inrush Current
  • Wide 2.7-V to 5.5-V Input Voltage Range
  • 40-V and 25-V Overvoltage Protection Options
  • 500-kHz Fixed Frequency Operation
  • 839-mA Peak Current Limit

2 Applications

  • Smartphone LCD Backlighting
  • Personal Navigation LCD Backlighting
  • 2 to 11 Series White-LED Backlit Display Power Source

3 Description

The LM3530 current mode boost converter supplies the power and controls the current in up to 11 series white LEDs. The 839-mA current limit and 2.7-V to 5.5-V input voltage range make the device a versatile backlight power source ideal for operation in portable applications.

The LED current is adjustable from 0 mA to 29.5 mA via an I2C-compatible interface. The 127 different current steps and 8 different maximum LED current levels give over 1000 programmable LED current levels. Additionally, PWM brightness control is possible through an external logic level input.

The device also features two Ambient Light Sensor inputs. These are designed to monitor analog output ambient light sensors and provide programmable adjustment of the LED current with changes in ambient light. Each ambient light sensor input has independently programmable internal voltage setting resistors which can be made high impedance to reduce power during shutdown. The 500-kHz switching frequency allows for high converter efficiency over a wide output voltage range accommodating from 2 to 11 series LEDs. Finally, the support of Content Adjusted Backlighting maximizes battery life while maintaining display image quality.

The LM3530 operates over the −40°C to 85°C temperature range.

Device Information(1)

PART NUMBER PACKAGE BODY SIZE (MAX)
LM3530 DSBGA (12) 1.64 mm x 1.24 mm
  1. For all available packages, see the orderable addendum at the end of the datasheet.

Simplified Schematic

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