DLPS202A October   2020  – August 2024 TPS99000S-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)
  9. 8 Power Supply Recommendations
    1. 8.1 TPS99000S-Q1 Power Supply Architecture
    2. 8.2 TPS99000S-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
7.2.1.2.6 Transimpedance Amplifiers (TIAs, Usage, Offset, Dark Current, Ranges, RGB Trim)

The TPS99000S-Q1 includes support for up to two system photodiode inputs.

TIA1 is used as the primary photo feedback channel. It supports 14 unique gain settings, spanning 0.75kV/A to 288kV/A. In addition, these gain settings can be adjusted downward by a high-resolution trim function, in a range of 1.0x to 0.2x. This trim function has independent RGB settings, supporting color rebalancing (such as trimming RGB feedback signals so that white light produces roughly equal voltages at TIA output for each color). Color rebalancing helps keep all three color channels in the working voltage range to maximize dynamic range. Figure 7-6 shows the TIA1 model.

TPS99000S-Q1 TIA1 Trim, Offset, and Gain StagesFigure 7-6 TIA1 Trim, Offset, and Gain Stages

TIA2 supports a single trim value and single dark offset value but is otherwise identical to TIA1.

Note:

TIA2 shall only be used for diagnostic purposes, and it is not recommended to use it for primary photo feedback amplification. If TIA2 is used to measure projector output or illumination light, this lack of multiplexed RGB parameters for trim and dark offset will limit its usage to looking only at one color at a time for situations where the highest gain settings are used in combination with high color to color electrical response imbalance. For lower gain settings or situations where the photodiode responses are naturally balanced, all 3 colors likely can be monitored with TIA2.

The trim settings may be used to lower the total gain of the TIA amplifiers. This provides flexibility to allow higher photodiode currents to be used without saturating the TIA.  For example, with the trim setting limited to 0.5×, a 0.75kV/A gain selection can be considered a 0.375kV/A effective gain setting.  The supported maximum photodiode current doubles in this case.

Both TIAs are designed to support a wide range of photodiode capacitances. A variable, internal compensation capacitor network is available to tune the circuit for maximum performance for a given photo diode and cable combination.

Both TIAs can be independently enabled or disabled. When a TIA is disabled, it is placed in a low-power mode to optimize power consumption.

TIA2 can be used for an over-brightness detection input or ADC measurements. It supports two outputs: 1) a higher bandwidth output, optimized for measuring photodiode response of CM bit slice light pulses, and 2) a much lower bandwidth output, optimized for measuring light flux filter over periods spanning at least one video frame. TIA1 supports these same two outputs, plus one more: a very high bandwidth output used for the real-time color control loop photo feedback. See Section 5.5 for BW and slew rate specifications for this use case.

One potential use for TIA2 is for system-level brightness detection.