DLPS071A October   2015  – February 2023 DLPA3005

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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 SPI Timing Parameters
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Description
    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 Auto LED Turn Off Functionality
          3. 7.3.1.2.3 Thermal Protection
      2. 7.3.2 Illumination
        1. 7.3.2.1 Programmable Gain Block
        2. 7.3.2.2 LDO Illumination
        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 Illumination Driver plus Power FETs Efficiency
      3. 7.3.3 External Power FET Selection
        1. 7.3.3.1 Threshold Voltage
        2. 7.3.3.2 Gate Charge and Gate Timing
        3. 7.3.3.3 RDS(ON)
      4. 7.3.4 DMD Supplies
        1. 7.3.4.1 LDO DMD
        2. 7.3.4.2 DMD HV Regulator
        3. 7.3.4.3 DMD/DLPC Buck Converters
        4. 7.3.4.4 DMD Monitoring
          1. 7.3.4.4.1 Power Good
          2. 7.3.4.4.2 Overvoltage Fault
      5. 7.3.5 Buck Converters
        1. 7.3.5.1 LDO Bucks
        2. 7.3.5.2 General Purpose Buck Converter
        3. 7.3.5.3 Buck Converter Monitoring
          1. 7.3.5.3.1 Power Good
          2. 7.3.5.3.2 Overvoltage Fault
        4. 7.3.5.4 Buck Converter Efficiency
      6. 7.3.6 Auxiliary LDOs
      7. 7.3.7 Measurement System
    4. 7.4 Device Functional Modes
    5. 7.5 Programming
      1. 7.5.1 SPI
      2. 7.5.2 Interrupt
      3. 7.5.3 Fast-Shutdown in Case of Fault
      4. 7.5.4 Protected Registers
    6. 7.6 Register Maps
  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 Component Selection for General-Purpose Buck Converters
      3. 8.2.3 Application Curve
    3. 8.3 System Example With DLPA3005 Internal Block Diagram
  9. 9 Power Supply Recommendations
    1. 9.1 Power-Up and Power-Down Timing
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 SPI Connections
      2. 10.1.2 RLIM Routing
      3. 10.1.3 LED Connection
    2. 10.2 Layout Example
    3. 10.3 Thermal Considerations
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Device Nomenclature
    2. 11.2 Third-Party Products Disclaimer
    3. 11.3 Related Links
    4. 11.4 Receiving Notification of Documentation Updates
    5. 11.5 Support Resources
    6. 11.6 Trademarks
    7. 11.7 Electrostatic Discharge Caution
    8. 11.8 Glossary
  12. 12Mechanical, Packaging, and Orderable Information
    1. 12.1 Package Option Addendum

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information
7.3.2.5.2 Ratio Metric Overvoltage Protection

The DLPA3005 illumination driver LED outputs are protected against open circuit use. In case no LED is connected and the DLPA3005 is instructed to set the LED current to a specific level, the LED voltage (ILLUM_A_FB) will quickly rise and potentially rail to VIN. This should be prevented. The OVP protection circuit triggers once VLED crosses a predefined level. As a result, the DLPA3005 is switched off.

The same protection circuit is triggered in case the supply voltage (VINA) will become too low to have the DLPA3005 work properly given the VLED level. This protection circuit is constructed around a comparator that will sense both the LED voltage and the VINA supply voltage. The fraction of the VINA is connected to the minus input of the comparator while the fraction of the VLED voltage is connected to the plus input. Triggering occurs when the plus input rises above the minus input and an OVP fault is set. The fraction of the VINA must be set between 1 V and 4 V to ensure proper operation of the comparator.

GUID-DA1D1B45-10FF-46D4-8CD1-1EC36CC70EB7-low.gif Figure 7-9 Ratio Metric OVP

The fraction of the ILLUM_A_FB voltage is set by the register VLED_OVP_VLED_RATIO, while the setting of the fraction of the VINA voltage is done by register VLED_OVP_VIN_RATIO. In general, an OVP fault is set when:

VLED/VLED_RATIO ≥ VINA/VINA_RATIO
thus when:
VLED ≥ VINA * VLED_RATIO/VINA_RATIO.

Clearly, the OVP level is ratio-metric; that is, can be set to a fixed fraction of VINA.