DLPS052 October   2015 DLPA3000


  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. Supply
        2. Monitoring
          1. Block Faults
          2. Low Battery and UVLO
          3. Auto LED Turn Off Functionality
          4. Thermal Protection
      2. 7.3.2 Illumination
        1. Programmable Gain Block
        2. LDO Illum
        3. Illumination Driver A
        4. RGB Strobe Decoder
          1. Break Before Make (BBM)
          2. Openloop Voltage
          3. Transient Current Limit
        5. Illumination Monitoring
          1. Power Good
          2. Ratio Metric Overvoltage Protection
        6. Load Current and Supply Voltage
        7. Illumination Driver Plus Power FETS Efficiency
      3. 7.3.3 DMD Supplies
        1. LDO DMD
        2. DMD HV Regulator
          1. Power-Up and Power-Down Timing
        3. DMD/DLPC Buck Converters
        4. DMD Monitoring
          1. Power Good
          2. Overvoltage Fault
      4. 7.3.4 Buck Converters
        1. LDO Bucks
        2. General Purpose Buck Converters
        3. Buck Converter Monitoring
          1. Power Good
          2. Overvoltage Fault
        4. Buck Converter Efficiency
      5. 7.3.5 Auxiliary LDOs
      6. 7.3.6 Measurement System
      7. 7.3.7 Digital Control
        1. SPI
        2. Interrupt
        3. Fast-Shutdown in Case of Fault
        4. Protected Registers
        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. Design Requirements
        2. Detailed Design Procedure
        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)

Measurement System

The measurement system (Figure 24) is designed to sense internal and external nodes and convert them to digital by the implemented AFE comparator. The AFE can be enabled through register 0x0A, AFE_EN. The reference signal for this comparator, ACMPR_REF, is a low pass filtered PWM signal coming from the DLPC. To be able to cover a wide range of input signals, a variable gain amplifier (VGA) is added with 3 gain settings (1x, 9.5x, and 18x). The gain of the VGA can be set through register 0x0A, AFE_GAIN. The maximum input voltage of the VGA is 1.5 V. However, some of the internal voltages are too large to be handled by the VGA and are divided down first.

DLPA3000 AFE.gifFigure 24. Measurement System

The multiplexer (MUX) connects to a wide range of nodes. Selection of the MUX input can be done through register 0x0A, AFE_SEL. Signals that can be selected:

  • System input voltage, SYSPWR
  • LED anode cathode voltage, ILLUM_A_FB
  • LED cathode voltage, CHx_SWITCH
  • V_RLIM to measure LED current
  • Internal reference, VREF_1V2
  • Die temperature represented by voltage VOTS
  • EEPROM programming voltage, VPROG1,2/12
  • LABB sensor, V_LABB
  • External sense pins, ACMPR_IN_1,2,3

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 1.5 V, whereas the system voltage can be as high as 20 V. The division is done internally in the DLPA3000. The division factor selection (VIN division factor) is combined with the AUTO_LED_TURN_OFF functionality of the illumination driver and can be set through register 0x18, ILLUM_LED_AUTO_OFF_SEL.

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 and can be set through register 0x19, VLED_OVP_VLED_RATIO. The cathode voltages CH1,2,3_SWITCH are fed directly to the MUX without division factor.

The LED current can be determined by knowing the value of sense resistor RLIM and the voltage across the resistor. The voltage at the top-side of the sense resistor can be measured by selecting 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 junction temperature of the chip: Temperature (°C) = 300 × VOTS (V) –270

For storage of trim bits, but also for the USER EEPROM bytes (0x30 to 0x35), the DLPA3000 has two EEPROM blocks. The programming voltage of EEPROM block 1 and 2 can be measured through MUX input VPROG1/12 and VPROGR2/12, respectively. The EEPROM programming voltage is divided by 12 before it is supplied to the MUX to prevent a too-large voltage on the MUX input. The EEPROM programming voltage is ≈12 V.

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. The light sensor signal is sampled and held such that it can be read independently of the sensor timing. To use this feature, it should be ensured that:

  • The AFE block is enabled (0x0A, AFE_EN = 1)
  • The LABB input is selected (0x0A, AFE_SEL<3:0>=3h)
  • The AFE gain is set appropriately to have AFE_Gain x VLABB < 1.5 V (0x0A, AFE_GAIN<1:0>)

Sampling of the signal can be done through one of the following methods:

  1. Writing to register 0x0B by specifying the sample time window (TSAMPLE_SEL) and set bit SAMPLE_LABB=1 to start sampling. The SAMPLE_LABB bit in register 0x0B is automatically reset to 0 at the end of the sample period to be ready for a next sample request.
  2. Use the input ACMPR_LABB_SAMPLE-pin as a sample signal. As long as this signal is high, the signal on ACMPR_IN_LABB is tracked. Once the ACMP_LABB_SAMPLE is set low again, the value at that moment will be held.

ACMPR_IN_1,2,3 can measure external signals from for instance a light sensor or a temperature sensor. It should be ensured that the voltage on the input does not exceed 1.5 V.