DLPS039G December   2015  – July 2024 TPS99000-Q1

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—Transimpedance Amplifier Parameters
    6. 5.6  Electrical Characteristics—Digital to Analog Converters
    7. 5.7  Electrical Characteristics—Analog to Digital Converter
    8. 5.8  Electrical Characteristics—FET Gate Drivers
    9. 5.9  Electrical Characteristics—Photo Comparator
    10. 5.10 Electrical Characteristics—Voltage Regulators
    11. 5.11 Electrical Characteristics—Temperature and Voltage Monitors
    12. 5.12 Electrical Characteristics—Current Consumption
    13. 5.13 Power-Up Timing Requirements
    14. 5.14 Power-Down Timing Requirements
    15. 5.15 Timing Requirements—Sequencer Clock
    16. 5.16 Timing Requirements—Host and Diagnostic Port SPI Interface
    17. 5.17 Timing Requirements—ADC Interface
    18. 5.18 Switching Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 Illumination Control
        1. 6.3.1.1 Illumination System High Dynamic Range Dimming Overview
        2. 6.3.1.2 Illumination Control Loop
        3. 6.3.1.3 Continuous Mode Operation
          1. 6.3.1.3.1 Output Capacitance in Continuous Mode
          2. 6.3.1.3.2 Continuous Mode Driver Distortion and Blanking Current
          3. 6.3.1.3.3 Continuous Mode S_EN2 Dissipative Load Shunt Options
          4. 6.3.1.3.4 Continuous Mode Constant OFF Time
          5. 6.3.1.3.5 Continuous Mode Current Limit
        4. 6.3.1.4 Discontinuous Mode Operation
          1. 6.3.1.4.1 Discontinuous Mode Pulse Width Limit
          2. 6.3.1.4.2 COMPOUT_LOW Timer in Discontinuous Operation
          3. 6.3.1.4.3 Dimming Within Discontinuous Operation Range
          4. 6.3.1.4.4 Multiple Pulse Heights to Increase Bit Depth
          5. 6.3.1.4.5 TIA Gain Adjustment
          6. 6.3.1.4.6 Current Limit in Discontinuous Mode
          7. 6.3.1.4.7 CMODE Big Cap Mode in Discontinuous Operation
      2. 6.3.2 Over-Brightness Detection
        1. 6.3.2.1 Photo Feedback Monitor BIST
        2. 6.3.2.2 Excessive Brightness BIST
      3. 6.3.3 Analog to Digital Converter
        1. 6.3.3.1 Analog to Digital Converter Input Table
      4. 6.3.4 Power Sequencing and Monitoring
        1. 6.3.4.1 Power Monitoring
      5. 6.3.5 DMD Mirror Voltage Regulator
      6. 6.3.6 Low Dropout Regulators
      7. 6.3.7 System Monitoring Features
        1. 6.3.7.1 Windowed Watchdog Circuits
        2. 6.3.7.2 Die Temperature Monitors
        3. 6.3.7.3 External Clock Ratio Monitor
      8. 6.3.8 Communication Ports
        1. 6.3.8.1 Serial Peripheral Interface (SPI)
    4. 6.4 Device Functional Modes
      1. 6.4.1 OFF
      2. 6.4.2 STANDBY
      3. 6.4.3 POWERING_DMD
      4. 6.4.4 DISPLAY_RDY
      5. 6.4.5 DISPLAY_ON
      6. 6.4.6 PARKING
      7. 6.4.7 SHUTDOWN
    5. 6.5 Register Maps
      1. 6.5.1 System Status Registers
      2. 6.5.2 ADC Control
      3. 6.5.3 General Fault Status
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Applications
      1. 7.2.1 HUD
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Application Design Considerations
          1. 7.2.1.2.1 Photodiode Considerations
          2. 7.2.1.2.2 LED Current Measurement
          3. 7.2.1.2.3 Setting the Current Limit
          4. 7.2.1.2.4 Input Voltage Variation Impact
          5. 7.2.1.2.5 Discontinuous Mode Photo Feedback Considerations
          6. 7.2.1.2.6 Transimpedance Amplifiers (TIAs, Usage, Offset, Dark Current, Ranges, RGB Trim)
      2. 7.2.2 Headlight
        1. 7.2.2.1 Design Requirements
  9. 8 Power Supply Recommendations
    1. 8.1 TPS99000-Q1 Power Supply Architecture
    2. 8.2 TPS99000-Q1 Power Outputs
    3. 8.3 Power Supply Architecture
  10. 9 Layout
    1. 9.1 Layout Guidelines
      1. 9.1.1 Power/High Current Signals
      2. 9.1.2 Sensitive Analog Signals
      3. 9.1.3 High-Speed Digital Signals
      4. 9.1.4 High Power Current Loops
      5. 9.1.5 Kelvin Sensing Connections
      6. 9.1.6 Ground Separation
  11. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Third-Party Products Disclaimer
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

6.3.2.1 Photo Feedback Monitor BIST

A disconnection of the primary photodiode breaks the feedback loop used to regulate LED output. Any disconnection of this photodiode should be detected so the LEDs can be disabled.

The DLPC23x-Q1 software and the TPS99000-Q1 implement a photo feedback monitor Built-In Self-Test (BIST) to detect a disconnected photodiode. Every video frame, the DLPC23x-Q1 software uses ADC measurements of the LED current and TIA output, and COMPOUT falling edges to detect a disconnected photodiode.

In continuous mode, the DLPC23x-Q1 software determines that the photodiode is disconnected if all the LED currents are at maximum, but the TIA measurements are at a minimum. This indicates that the LEDs are conducting current, but the photodiode is not responding to light output from the LEDs.

In discontinuous mode, COMPOUT edges are used to detect a photodiode disconnect. A falling edge on COMPOUT indicates that an LED pulse has reached the desired threshold. This is only possible if the photodiode is connected. Therefore, the COMPOUT edges are detected by the DLPC23x-Q1 software to determine if the photodiode is connected.