DLPS240A June   2024  – August 2024 DLPA3085

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information
    5. 5.5 Electrical Characteristics
    6. 5.6 SPI Timing Parameters
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Description
    3. 6.3 Feature Description
      1. 6.3.1 Supply and Monitoring
        1. 6.3.1.1 Supply
        2. 6.3.1.2 Monitoring
          1. 6.3.1.2.1 Block Faults
          2. 6.3.1.2.2 Auto LED Turn-Off Functionality
          3. 6.3.1.2.3 Thermal Protection
      2. 6.3.2 Illumination
        1. 6.3.2.1 Programmable Gain Block
        2. 6.3.2.2 LDO Illumination
        3. 6.3.2.3 Illumination Driver A
        4. 6.3.2.4 RGB Strobe Decoder
          1. 6.3.2.4.1 Break Before Make (BBM)
          2. 6.3.2.4.2 Openloop Voltage
          3. 6.3.2.4.3 Transient Current Limit
        5. 6.3.2.5 Illumination Monitoring
          1. 6.3.2.5.1 Power Good
          2. 6.3.2.5.2 Ratio Metric Overvoltage Protection
        6. 6.3.2.6 Illumination Driver Plus Power FETs Efficiency
      3. 6.3.3 External Power FET Selection
        1. 6.3.3.1 Threshold Voltage
        2. 6.3.3.2 Gate Charge and Gate Timing
        3. 6.3.3.3 RDS(ON)
      4. 6.3.4 DMD Supplies
        1. 6.3.4.1 LDO DMD
        2. 6.3.4.2 DMD HV Regulator
        3. 6.3.4.3 DMD/DLPC Buck Converters
        4. 6.3.4.4 DMD Monitoring
          1. 6.3.4.4.1 Power Good
          2. 6.3.4.4.2 Overvoltage Fault
      5. 6.3.5 Buck Converters
        1. 6.3.5.1 LDO Bucks
        2. 6.3.5.2 General Purpose Buck Converters
        3. 6.3.5.3 Buck Converter Monitoring
          1. 6.3.5.3.1 Power Good
          2. 6.3.5.3.2 Overvoltage Fault
        4. 6.3.5.4 Buck Converter Efficiency
      6. 6.3.6 Auxiliary LDOs
      7. 6.3.7 Measurement System
    4. 6.4 Device Functional Modes
    5. 6.5 Programming
      1. 6.5.1 SPI
      2. 6.5.2 Interrupt
      3. 6.5.3 Fast-Shutdown in Case of Fault
    6. 6.6 Register Maps
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Component Selection for General-Purpose Buck Converter
      3. 7.2.3 Application Curve
    3. 7.3 System Example With DLPA3085 Internal Block Diagram
  9. 8 Power Supply Recommendations
    1. 8.1 Power-Up and Power-Down Timing
  10. 9 Layout
    1. 9.1 Layout Guidelines
      1. 9.1.1 SPI Connections
      2. 9.1.2 RLIM Routing
      3. 9.1.3 LED Connection
    2. 9.2 Layout Example
    3. 9.3 Thermal Considerations
  11. 10Device and Documentation Support
    1. 10.1 Third-Party Products Disclaimer
    2. 10.2 Device Support
      1. 10.2.1 Device Nomenclature
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

6.3.2 Illumination

The illumination function includes all blocks needed to generate light for the DLP system. To accurately set the current through the LEDs, a control loop is used (Figure 6-2). The intended LED current is set through IDAC[9:0]. The Illumination driver controls the LED anode voltage VLED and as a result a current will flow through one of the LEDs. The LED current is measured from the voltage across sense resistor RLIM. Based on the difference between the actual and intended current, the loop controls the output of the buck converter (VLED) higher or lower. The LED that conducts the current is controlled by switches P, Q, and R. The Openloop feedback circuitry ensures that the control loop can be closed for cases when there is no path through the LED (for instance, when ILED= 0).

DLPA3085 Illumination Control LoopFigure 6-2 Illumination Control Loop

Within the illumination block, the following blocks can be distinguished:

  • Programmable gain block
  • LDO ILLUM, the analog supply voltage for internal illumination blocks
  • Illumination driver A, the primary driver for the external FETs
  • Illumination driver B, secondary driver – for future purposes
  • RGB strobe decoder, driver for external switches to control the on-off rhythm of the LEDs and measures the LED current