SNVS598B August   2010  – March 2018 LM3535

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin 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 Charge Pump
      2. 7.3.2 Diode Current Sinks
      3. 7.3.3 Ambient Light Sensing (ALS) And Interrupt
      4. 7.3.4 Dynamic Backlight Control Input (PWM Pin)
      5. 7.3.5 LED Forward Voltage Monitoring
      6. 7.3.6 Configurable Gain Transition Delay
      7. 7.3.7 Hardware Enable (HWEN)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown
      2. 7.4.2 Standby
      3. 7.4.3 Active Mode
    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
        5. 7.5.1.5 Internal Registers of LM3535
  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 Ambient Light Sensing
          1. 8.2.2.1.1 Ambient Light Sensor Block
          2. 8.2.2.1.2 ALS Operation
            1. 8.2.2.1.2.1 ALS Configuration Example
          3. 8.2.2.1.3 ALS Averaging Time
          4. 8.2.2.1.4 Ambient Light Current Control + PWM
            1. 8.2.2.1.4.1 ALS + PWM Example
        2. 8.2.2.2 LED Configurations
        3. 8.2.2.3 Maximum Output Current, Maximum LED Voltage, Minimum Input Voltage
          1. 8.2.2.3.1 Total Output Current Capability
        4. 8.2.2.4 Parallel Connected and Unused Outputs
        5. 8.2.2.5 Power Efficiency
        6. 8.2.2.6 Power Dissipation
        7. 8.2.2.7 Thermal Protection
        8. 8.2.2.8 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 Receiving Notification of Documentation Updates
    2. 11.2 Community Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.3.3 Ambient Light Sensing (ALS) And Interrupt

The LM3535 provides an ambient light sensing input for use with ambient backlight control. By connecting the anode of a photo diode / sensor to the sensor input pins, and configuring the appropriate ALS resistors, the LM3535 can be configured to adjust the diode current to five unique settings, corresponding to four adjustable light region trip points. Additionally, when the LM3535 determines that an ambient condition has changed, the interrupt pin, when connected to a pullup resistor toggles to a 0 alerting the controller. See I2C Compatible Interface for more details regarding the register configurations.