SNLS454A November   2014  – March 2019 DS90UB947-Q1


  1. Features
  2. Applications
  3. Description
    1.     Device Images
      1.      Applications 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  DC Electrical Characteristics
    6. 6.6  AC Electrical Characteristics
    7. 6.7  DC and AC Serial Control Bus Characteristics
    8. 6.8  Recommended Timing for the Serial Control Bus
    9. 6.9  Timing Diagrams
    10. 6.10 Typical Characteristics
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  High-Speed Forward Channel Data Transfer
      2. 7.3.2  Back Channel Data Transfer
      3. 7.3.3  FPD-Link III Port Register Access
      4. 7.3.4  OpenLDI Input Frame and Color Bit Mapping Select
      5. 7.3.5  Video Control Signals
      6. 7.3.6  Power Down (PDB)
      7. 7.3.7  Serial Link Fault Detect
      8. 7.3.8  Interrupt Pin (INTB)
      9. 7.3.9  Remote Interrupt Pin (REM_INTB)
      10. 7.3.10 General-Purpose I/O
        1. GPIO[3:0] Configuration
        2. Back Channel Configuration
        3. GPIO_REG[8:5] Configuration
      11. 7.3.11 SPI Communication
        1. SPI Mode Configuration
        2. Forward Channel SPI Operation
        3. Reverse Channel SPI Operation
      12. 7.3.12 Backward Compatibility
      13. 7.3.13 Audio Modes
        1. I2S Audio Interface
          1. I2S Transport Modes
          2. I2S Repeater
        2. TDM Audio Interface
      14. 7.3.14 Repeater
        1. Repeater Configuration
        2. Repeater Connections
          1. Repeater Fan-Out Electrical Requirements
      15. 7.3.15 Built-In Self Test (BIST)
        1. BIST Configuration and Status
        2. Forward Channel and Back Channel Error Checking
      16. 7.3.16 Internal Pattern Generation
        1. Pattern Options
        2. Color Modes
        3. Video Timing Modes
        4. External Timing
        5. Pattern Inversion
        6. Auto Scrolling
        7. Additional Features
    4. 7.4 Device Functional Modes
      1. 7.4.1 Mode Select Configuration Settings (MODE_SEL[1:0])
      2. 7.4.2 FPD-Link III Modes of Operation
        1. Single Link Operation
        2. Dual Link Operation
        3. Replicate Mode
        4. Auto-Detection of FPD-Link III Modes
    5. 7.5 Programming
      1. 7.5.1 Serial Control Bus
      2. 7.5.2 Multi-Master Arbitration Support
      3. 7.5.3 I2C Restrictions on Multi-Master Operation
      4. 7.5.4 Multi-Master Access to Device Registers for Newer FPD-Link III Devices
      5. 7.5.5 Multi-Master Access to Device Registers for Older FPD-Link III Devices
      6. 7.5.6 Restrictions on Control Channel Direction for Multi-Master Operation
    6. 7.6 Register Maps
  8. Application and Implementation
    1. 8.1 Applications Information
    2. 8.2 Typical Applications
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. High-Speed Interconnect Guidelines
      3. 8.2.3 Application Curves
        1. Application Performance Plots
  9. Power Supply Recommendations
    1. 9.1 Power-Up Requirements and PDB Pin
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Trademarks
    3. 11.3 Electrostatic Discharge Caution
    4. 11.4 Glossary
  12. 12Mechanical, Packaging and Orderable Information

Package Options

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

Layout Guidelines

Circuit board layout and stack-up for the LVDS serializer and deserializer devices should be designed to provide low-noise power to the device. Good layout practice will also separate high frequency or high-level inputs and outputs to minimize unwanted stray noise, feedback and interference. Power system performance may be greatly improved by using thin dielectrics (2 to 4 mil) for power / ground sandwiches. This arrangement utilizes the plane capacitance for the PCB power system and has low-inductance, which has proven effectiveness especially at high frequencies, and makes the value and placement of external bypass capacitors less critical. External bypass capacitors should include both RF ceramic and tantalum electrolytic types. RF capacitors may use values in the range of 0.01 μF to 10 μF. Tantalum capacitors may be in the 2.2-μF to 10-μF range. The voltage rating of the tantalum capacitors should be at least 5X the power supply voltage being used.

MLCC surface mount capacitors are recommended due to their smaller parasitic properties. When using multiple capacitors per supply pin, locate the smaller value closer to the pin. A large bulk capacitor is recommended at the point of power entry. This is typically in the 50μF to 100μF range and will smooth low frequency switching noise. It is recommended to connect power and ground pins directly to the power and ground planes with bypass capacitors connected to the plane with via on both ends of the capacitor. Connecting power or ground pins to an external bypass capacitor will increase the inductance of the path. A small body size X7R chip capacitor, such as 0603 or 0805, is recommended for external bypass. A small body sized capacitor has less inductance. The user must pay attention to the resonance frequency of these external bypass capacitors, usually in the range of 20 MHz to 30 MHz. To provide effective bypassing, multiple capacitors are often used to achieve low impedance between the supply rails over the frequency of interest. At high frequency, it is also a common practice to use two vias from power and ground pins to the planes, reducing the impedance at high frequency.

Some devices provide separate power and ground pins for different portions of the circuit. This is done to isolate switching noise effects between different sections of the circuit. Separate planes on the PCB are typically not required. Pin Description tables typically provide guidance on which circuit blocks are connected to which power pin pairs. In some cases, an external filter many be used to provide clean power to sensitive circuits such as PLLs. For DS90UB947-Q1, only one common ground plane is required to connect all device related ground pins.

Use at least a four layer board with a power and ground plane. Locate LVCMOS signals away from the LVDS lines to prevent coupling from the LVCMOS lines to the LVDS lines. Closely coupled differential lines of 100 Ω are typically recommended for LVDS interconnect. The closely coupled lines help to ensure that coupled noise will appear as common mode and thus is rejected by the receivers. The tightly coupled lines will also radiate less.

At least 9 thermal vias are necessary from the device center DAP to the ground plane. They connect the device ground to the PCB ground plane, as well as conduct heat from the exposed pad of the package to the PCB ground plane. More information on the LLP style package, including PCB design and manufacturing requirements, is provided in the AN-1187 Leadless Leadframe Package (LLP) (SNOA401).