DLPS240A June   2024  – August 2024 DLPA3085

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
    6. 5.6 SPI Timing Parameters
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Description
    3. 6.3 Feature Description
      1. 6.3.1 Supply and Monitoring
        1. 6.3.1.1 Supply
        2. 6.3.1.2 Monitoring
          1. 6.3.1.2.1 Block Faults
          2. 6.3.1.2.2 Auto LED Turn-Off Functionality
          3. 6.3.1.2.3 Thermal Protection
      2. 6.3.2 Illumination
        1. 6.3.2.1 Programmable Gain Block
        2. 6.3.2.2 LDO Illumination
        3. 6.3.2.3 Illumination Driver A
        4. 6.3.2.4 RGB Strobe Decoder
          1. 6.3.2.4.1 Break Before Make (BBM)
          2. 6.3.2.4.2 Openloop Voltage
          3. 6.3.2.4.3 Transient Current Limit
        5. 6.3.2.5 Illumination Monitoring
          1. 6.3.2.5.1 Power Good
          2. 6.3.2.5.2 Ratio Metric Overvoltage Protection
        6. 6.3.2.6 Illumination Driver Plus Power FETs Efficiency
      3. 6.3.3 External Power FET Selection
        1. 6.3.3.1 Threshold Voltage
        2. 6.3.3.2 Gate Charge and Gate Timing
        3. 6.3.3.3 RDS(ON)
      4. 6.3.4 DMD Supplies
        1. 6.3.4.1 LDO DMD
        2. 6.3.4.2 DMD HV Regulator
        3. 6.3.4.3 DMD/DLPC Buck Converters
        4. 6.3.4.4 DMD Monitoring
          1. 6.3.4.4.1 Power Good
          2. 6.3.4.4.2 Overvoltage Fault
      5. 6.3.5 Buck Converters
        1. 6.3.5.1 LDO Bucks
        2. 6.3.5.2 General Purpose Buck Converters
        3. 6.3.5.3 Buck Converter Monitoring
          1. 6.3.5.3.1 Power Good
          2. 6.3.5.3.2 Overvoltage Fault
        4. 6.3.5.4 Buck Converter Efficiency
      6. 6.3.6 Auxiliary LDOs
      7. 6.3.7 Measurement System
    4. 6.4 Device Functional Modes
    5. 6.5 Programming
      1. 6.5.1 SPI
      2. 6.5.2 Interrupt
      3. 6.5.3 Fast-Shutdown in Case of Fault
    6. 6.6 Register Maps
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Application
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 Component Selection for General-Purpose Buck Converter
      3. 7.2.3 Application Curve
    3. 7.3 System Example With DLPA3085 Internal Block Diagram
  9. 8 Power Supply Recommendations
    1. 8.1 Power-Up and Power-Down Timing
  10. 9 Layout
    1. 9.1 Layout Guidelines
      1. 9.1.1 SPI Connections
      2. 9.1.2 RLIM Routing
      3. 9.1.3 LED Connection
    2. 9.2 Layout Example
    3. 9.3 Thermal Considerations
  11. 10Device and Documentation Support
    1. 10.1 Third-Party Products Disclaimer
    2. 10.2 Device Support
      1. 10.2.1 Device Nomenclature
    3. 10.3 Receiving Notification of Documentation Updates
    4. 10.4 Support Resources
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

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

6.3.7 Measurement System

The measurement system (Figure 6-18) is designed to sense internal and external nodes and convert them to digital by the implemented AFE comparator. The reference signal for this comparator, ACMPR_REF, is a low-pass filtered PWM signal coming from the DLPC. To cover a wide range of input signals, a variable gain amplifier (VGA) is added with three gain settings (1x, 9.5x, and 18x). The maximum input voltage of the VGA is 1.5V. However, some of the internal voltages are too large to be handled by the VGA and are divided down first.

DLPA3085 Measurement System Schematic Figure 6-18 Measurement System Schematic

The system input voltage SYSPWR can be measured by selecting the SYSPWR/xx input of the MUX. Before the system input voltage is supplied to the MUX, the voltage needs to be divided. This is because the variable gain amplifier (VGA) can handle voltages up to 1.5V, whereas the system voltage can be as high as 20V. The division is done internally in the DLPA3085. The division factor selection (VIN division factor) is combined with the AUTO_LED_TURN_OFF functionality of the illumination driver.

The LED voltages can be monitored by measuring both the common anode of the LEDs, as well as the cathode of each LED individually. The LED anode voltage (VLED) is measured by sensing the feedback pin of the illumination driver (ILLUM_A_FB). Like the SYSPWR, the LED anode voltage needs to be divided before feeding it to the MUX. The division factor is combined with the overvoltage fault level of the illumination driver. The cathode voltages CH1,2,3_SWITCH are fed directly to the MUX without a division factor.

The LED current can be determined by knowing the value of the sense resistor RLIM and the voltage across the resistor. The voltage at the top side of the sense resistor can be measured through MUX-input RLIM_K1. The bottom side of the resistor is connected to GND.

VOTS is connected to an on-chip temperature sensor. The voltage is a measure for the chip’s junction temperature: Temperature (°C) = 300 × VOTS (V) – 270.

LABB is a feature that stands for Local Area Brightness Boost. LABB locally increases the brightness while maintaining good contrast and saturation. The sensor needed for this feature should be connected to pin ACMPR_IN_LABB.

ACMPR_IN_1,2,3 can measure external signals from for instance a temperature sensor. Ensure the voltage on the input does not exceed 1.5V.