DLPS052 October   2015 DLPA3000

PRODUCTION DATA.  

  1. Features
  2. Applications
  3. Description
    1.     Device Images
      1.      Block Diagram
  4. Revision History
  5. Pin Configuration and Functions
    1.     Pin Functions
  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 SPI Timing Parameters
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Supply and Monitoring
        1. 7.3.1.1 Supply
        2. 7.3.1.2 Monitoring
          1. 7.3.1.2.1 Block Faults
          2. 7.3.1.2.2 Low Battery and UVLO
          3. 7.3.1.2.3 Auto LED Turn Off Functionality
          4. 7.3.1.2.4 Thermal Protection
      2. 7.3.2 Illumination
        1. 7.3.2.1 Programmable Gain Block
        2. 7.3.2.2 LDO Illum
        3. 7.3.2.3 Illumination Driver A
        4. 7.3.2.4 RGB Strobe Decoder
          1. 7.3.2.4.1 Break Before Make (BBM)
          2. 7.3.2.4.2 Openloop Voltage
          3. 7.3.2.4.3 Transient Current Limit
        5. 7.3.2.5 Illumination Monitoring
          1. 7.3.2.5.1 Power Good
          2. 7.3.2.5.2 Ratio Metric Overvoltage Protection
        6. 7.3.2.6 Load Current and Supply Voltage
        7. 7.3.2.7 Illumination Driver Plus Power FETS Efficiency
      3. 7.3.3 DMD Supplies
        1. 7.3.3.1 LDO DMD
        2. 7.3.3.2 DMD HV Regulator
          1. 7.3.3.2.1 Power-Up and Power-Down Timing
        3. 7.3.3.3 DMD/DLPC Buck Converters
        4. 7.3.3.4 DMD Monitoring
          1. 7.3.3.4.1 Power Good
          2. 7.3.3.4.2 Overvoltage Fault
      4. 7.3.4 Buck Converters
        1. 7.3.4.1 LDO Bucks
        2. 7.3.4.2 General Purpose Buck Converters
        3. 7.3.4.3 Buck Converter Monitoring
          1. 7.3.4.3.1 Power Good
          2. 7.3.4.3.2 Overvoltage Fault
        4. 7.3.4.4 Buck Converter Efficiency
      5. 7.3.5 Auxiliary LDOs
      6. 7.3.6 Measurement System
      7. 7.3.7 Digital Control
        1. 7.3.7.1 SPI
        2. 7.3.7.2 Interrupt
        3. 7.3.7.3 Fast-Shutdown in Case of Fault
        4. 7.3.7.4 Protected Registers
        5. 7.3.7.5 Writing to EEPROM
    4. 7.4 Device Functional Modes
    5. 7.5 Register Maps
  8. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Applications
      1. 8.2.1 Typical Application Setup Using DLPA3000
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
        3. 8.2.1.3 Application Curve
      2. 8.2.2 Typical Application with DLPA3000 Internal Block Diagram
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
    3. 10.3 SPI Connections
    4. 10.4 RLIM Routing
    5. 10.5 LED Connection
    6. 10.6 Thermal Considerations
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Device Nomenclature
    2. 11.2 Related Links
    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
    1. 12.1 Package Option Addendum
      1. 12.1.1 Packaging Information

Package Options

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

Illumination

The illumination function includes all blocks needed to generate light for the DLP system. In order to set accurately the current through the LEDs a control loop is used (Figure 5). The intended LED current is set via 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 via 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. Which LED 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 via the LED, for instance when ILED= 0.

DLPA3000 Illum_Control.gifFigure 5. Illumination Control Loop

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

  • Programmable gain block
  • LDO illum: analog supply voltage for internal illumination blocks.
  • Illumination driver A: primary driver using internal FETs.
  • Illumination driver B: secondary driver – for future purpose; will not be discussed.
  • RGB stobe decoder: controls the on-off rhythm of the LEDs and measures the LED current.