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)

Transient Current Limit

Typically the forward voltages of the GREEN and BLUE diodes are close to each other (about 3 V to 5 V) however the forward voltage of the red diode is significantly lower (2 V to 4 V). This can lead to a current spike in the RED diode when the strobe controller switches from green or blue to red. This happens because VLED is initially at a higher voltage than required to drive the red diode. DLPA3000 provides transient current limiting for each switch to limit the current in the LEDs during the transition. The transient current limit value is controlled through register 0x02 (ILLUM_ILIM). In a typical application it is required only for the RED diode. The value for ILLUM_ILIM should be set at least 20% higher than the DC regulation current. Register 0x02 (ILLUM_SW_ILIM_EN) contains three bits to select which switch employs the transient current limiting feature. The effect of the transient current limit on the LED current is shown in Figure 10.

DLPA3000 Transient_Current.gifFigure 10. LED Current Without (Left) and With (Right) Transient Current Limit