SPRS989F December   2016  – December 2018 DRA74P , DRA75P

PRODUCTION DATA.  

  1. 1Device Overview
    1. 1.1 Features
    2. 1.2 Applications
    3. 1.3 Description
    4. 1.4 Functional Block Diagram
  2. 2Revision History
  3. 3Device Comparison
    1. 3.1 Device Comparison Table
    2. 3.2 Related Products
  4. 4Terminal Configuration and Functions
    1. 4.1 Pin Diagram
    2. 4.2 Pin Attributes
    3. 4.3 Signal Descriptions
      1. 4.3.1  VIP
      2. 4.3.2  DSS
      3. 4.3.3  HDMI
      4. 4.3.4  EMIF
      5. 4.3.5  GPMC
      6. 4.3.6  Timers
      7. 4.3.7  I2C
      8. 4.3.8  HDQ1W
      9. 4.3.9  UART
      10. 4.3.10 McSPI
      11. 4.3.11 QSPI
      12. 4.3.12 McASP
      13. 4.3.13 USB
      14. 4.3.14 SATA
      15. 4.3.15 PCIe
      16. 4.3.16 DCAN and MCAN
      17. 4.3.17 GMAC_SW
      18. 4.3.18 MLB
      19. 4.3.19 eMMC/SD/SDIO
      20. 4.3.20 GPIO
      21. 4.3.21 KBD
      22. 4.3.22 PWM
      23. 4.3.23 ATL
      24. 4.3.24 Test Interfaces
      25. 4.3.25 System and Miscellaneous
        1. 4.3.25.1 Sysboot
        2. 4.3.25.2 PRCM
        3. 4.3.25.3 RTC
        4. 4.3.25.4 SDMA
        5. 4.3.25.5 INTC
        6. 4.3.25.6 Observability
        7. 4.3.25.7 Power Supplies
    4. 4.4 Pin Multiplexing
    5. 4.5 Connections for Unused Pins
  5. 5Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  Power-On Hours (POH)
    4. 5.4  Recommended Operating Conditions
    5. 5.5  Operating Performance Points
      1. 5.5.1 AVS and ABB Requirements
      2. 5.5.2 Voltage And Core Clock Specifications
      3. 5.5.3 Maximum Supported Frequency
    6. 5.6  Power Consumption Summary
    7. 5.7  Electrical Characteristics
      1. Table 5-6  LVCMOS DDR DC Electrical Characteristics
      2. Table 5-7  Dual Voltage LVCMOS I2C DC Electrical Characteristics
      3. Table 5-8  IQ1833 Buffers DC Electrical Characteristics
      4. Table 5-9  IHHV1833 Buffers DC Electrical Characteristics
      5. Table 5-10 LVCMOS OSC Buffers DC Electrical Characteristics
      6. Table 5-11 BMLB18 Buffers DC Electrical Characteristics
      7. Table 5-12 BC1833IHHV Buffers DC Electrical Characteristics
      8. Table 5-13 Dual Voltage SDIO1833 DC Electrical Characteristics
      9. Table 5-14 Dual Voltage LVCMOS DC Electrical Characteristics
      10. 5.7.1      HDMIPHY DC Electrical Characteristics
      11. 5.7.2      USBPHY DC Electrical Characteristics
      12. 5.7.3      SATAPHY DC Electrical Characteristics
      13. 5.7.4      PCIEPHY DC Electrical Characteristics
    8. 5.8  VPP Specifications for One-Time Programmable (OTP) eFuses
      1. Table 5-15 Recommended Operating Conditions for OTP eFuse Programming
      2. 5.8.1      Hardware Requirements
      3. 5.8.2      Programming Sequence
      4. 5.8.3      Impact to Your Hardware Warranty
    9. 5.9  Thermal Resistance Characteristics
      1. 5.9.1 Package Thermal Characteristics
    10. 5.10 Timing Requirements and Switching Characteristics
      1. 5.10.1 Timing Parameters and Information
        1. 5.10.1.1 Parameter Information
          1. 5.10.1.1.1 1.8V and 3.3V Signal Transition Levels
          2. 5.10.1.1.2 1.8V and 3.3V Signal Transition Rates
          3. 5.10.1.1.3 Timing Parameters and Board Routing Analysis
      2. 5.10.2 Interface Clock Specifications
        1. 5.10.2.1 Interface Clock Terminology
        2. 5.10.2.2 Interface Clock Frequency
      3. 5.10.3 Power Supply Sequences
      4. 5.10.4 Clock Specifications
        1. 5.10.4.1 Input Clocks / Oscillators
          1. 5.10.4.1.1 OSC0 External Crystal
          2. 5.10.4.1.2 OSC0 Input Clock
          3. 5.10.4.1.3 Auxiliary Oscillator OSC1 Input Clock
            1. 5.10.4.1.3.1 OSC1 External Crystal
            2. 5.10.4.1.3.2 OSC1 Input Clock
          4. 5.10.4.1.4 RTC Oscillator Input Clock
            1. 5.10.4.1.4.1 RTC Oscillator External Crystal
            2. 5.10.4.1.4.2 RTC Oscillator Input Clock
        2. 5.10.4.2 RC On-die Oscillator Clock
        3. 5.10.4.3 Output Clocks
        4. 5.10.4.4 DPLLs, DLLs
          1. 5.10.4.4.1 DPLL Characteristics
          2. 5.10.4.4.2 DLL Characteristics
          3. 5.10.4.4.3 DPLL and DLL Noise Isolation
      5. 5.10.5 Recommended Clock and Control Signal Transition Behavior
      6. 5.10.6 Peripherals
        1. 5.10.6.1  Timing Test Conditions
        2. 5.10.6.2  Virtual and Manual I/O Timing Modes
        3. 5.10.6.3  VIP
        4. 5.10.6.4  DSS
        5. 5.10.6.5  HDMI
        6. 5.10.6.6  EMIF
        7. 5.10.6.7  GPMC
          1. 5.10.6.7.1 GPMC/NOR Flash Interface Synchronous Timing
          2. 5.10.6.7.2 GPMC/NOR Flash Interface Asynchronous Timing
          3. 5.10.6.7.3 GPMC/NAND Flash Interface Asynchronous Timing
        8. 5.10.6.8  Timers
        9. 5.10.6.9  I2C
          1. Table 5-64 Timing Requirements for I2C Input Timings
          2. Table 5-65 Timing Requirements for I2C HS-Mode (I2C3/4/5 Only)
          3. Table 5-66 Switching Characteristics Over Recommended Operating Conditions for I2C Output Timings
        10. 5.10.6.10 HDQ1W
          1. 5.10.6.10.1 HDQ / 1-Wire — HDQ Mode
          2. 5.10.6.10.2 HDQ/1-Wire—1-Wire Mode
        11. 5.10.6.11 UART
          1. Table 5-71 Timing Requirements for UART
          2. Table 5-72 Switching Characteristics Over Recommended Operating Conditions for UART
        12. 5.10.6.12 McSPI
        13. 5.10.6.13 QSPI
        14. 5.10.6.14 McASP
          1. Table 5-79 Timing Requirements for McASP1
          2. Table 5-80 Timing Requirements for McASP2
          3. Table 5-81 Timing Requirements for McASP3/4/5/6/7/8
          4. Table 5-82 Switching Characteristics Over Recommended Operating Conditions for McASP1
          5. Table 5-83 Switching Characteristics Over Recommended Operating Conditions for McASP2
          6. Table 5-84 Switching Characteristics Over Recommended Operating Conditions for McASP3/4/5/6/7/8
        15. 5.10.6.15 USB
          1. 5.10.6.15.1 USB1 DRD PHY
          2. 5.10.6.15.2 USB2 PHY
          3. 5.10.6.15.3 USB3 and USB4 DRD ULPI—SDR—Slave Mode—12-pin Mode
        16. 5.10.6.16 SATA
        17. 5.10.6.17 PCIe
        18. 5.10.6.18 CAN
          1. 5.10.6.18.1 DCAN
          2. 5.10.6.18.2 MCAN-FD
          3. Table 5-99  Timing Requirements for CANx Receive
          4. Table 5-100 Switching Characteristics Over Recommended Operating Conditions for CANx Transmit
        19. 5.10.6.19 GMAC_SW
          1. 5.10.6.19.1 GMAC MII Timings
            1. Table 5-101 Timing Requirements for miin_rxclk - MII Operation
            2. Table 5-102 Timing Requirements for miin_txclk - MII Operation
            3. Table 5-103 Timing Requirements for GMAC MIIn Receive 10/100 Mbit/s
            4. Table 5-104 Switching Characteristics Over Recommended Operating Conditions for GMAC MIIn Transmit 10/100 Mbits/s
          2. 5.10.6.19.2 GMAC MDIO Interface Timings
          3. 5.10.6.19.3 GMAC RMII Timings
            1. Table 5-109 Timing Requirements for GMAC REF_CLK - RMII Operation
            2. Table 5-110 Timing Requirements for GMAC RMIIn Receive
            3. Table 5-111 Switching Characteristics Over Recommended Operating Conditions for GMAC REF_CLK - RMII Operation
            4. Table 5-112 Switching Characteristics Over Recommended Operating Conditions for GMAC RMIIn Transmit 10/100 Mbits/s
          4. 5.10.6.19.4 GMAC RGMII Timings
            1. Table 5-116 Timing Requirements for rgmiin_rxc - RGMIIn Operation
            2. Table 5-117 Timing Requirements for GMAC RGMIIn Input Receive for 10/100/1000 Mbps
            3. Table 5-118 Switching Characteristics Over Recommended Operating Conditions for rgmiin_txctl - RGMIIn Operation for 10/100/1000 Mbit/s
            4. Table 5-119 Switching Characteristics for GMAC RGMIIn Output Transmit for 10/100/1000 Mbps
        20. 5.10.6.20 MLB
        21. 5.10.6.21 eMMC/SD/SDIO
          1. 5.10.6.21.1 MMC1—SD Card Interface
            1. 5.10.6.21.1.1 Default speed, 4-bit data, SDR, half-cycle
            2. 5.10.6.21.1.2 High speed, 4-bit data, SDR, half-cycle
            3. 5.10.6.21.1.3 SDR12, 4-bit data, half-cycle
            4. 5.10.6.21.1.4 SDR25, 4-bit data, half-cycle
            5. 5.10.6.21.1.5 UHS-I SDR50, 4-bit data, half-cycle
            6. 5.10.6.21.1.6 UHS-I SDR104, 4-bit data, half-cycle
            7. 5.10.6.21.1.7 UHS-I DDR50, 4-bit data
          2. 5.10.6.21.2 MMC2 — eMMC
            1. 5.10.6.21.2.1 Standard JC64 SDR, 8-bit data, half cycle
            2. 5.10.6.21.2.2 High-Speed JC64 SDR, 8-bit data, half cycle
            3. 5.10.6.21.2.3 High-Speed HS200 JC64 SDR, 8-bit data, half cycle
            4. 5.10.6.21.2.4 High-Speed JC64 DDR, 8-bit data
          3. 5.10.6.21.3 MMC3 and MMC4—SDIO/SD
            1. 5.10.6.21.3.1 MMC3 and MMC4, SD Default Speed
            2. 5.10.6.21.3.2 MMC3 and MMC4, SD High Speed
            3. 5.10.6.21.3.3 MMC3 and MMC4, SD and SDIO SDR12 Mode
            4. 5.10.6.21.3.4 MMC3 and MMC4, SD SDR25 Mode
            5. 5.10.6.21.3.5 MMC3 SDIO High-Speed UHS-I SDR50 Mode, Half Cycle
        22. 5.10.6.22 GPIO
        23. 5.10.6.23 ATL
          1. 5.10.6.23.1 ATL Electrical Data/Timing
            1. Table 5-175 Switching Characteristics Over Recommended Operating Conditions for ATL_CLKOUTx
        24. 5.10.6.24 System and Miscellaneous Interfaces
      7. 5.10.7 Emulation and Debug Subsystem
        1. 5.10.7.1 JTAG
          1. 5.10.7.1.1 JTAG Electrical Data/Timing
            1. Table 5-176 Timing Requirements for IEEE 1149.1 JTAG
            2. Table 5-177 Switching Characteristics Over Recommended Operating Conditions for IEEE 1149.1 JTAG
            3. Table 5-178 Timing Requirements for IEEE 1149.1 JTAG With RTCK
            4. Table 5-179 Switching Characteristics Over Recommended Operating Conditions for IEEE 1149.1 JTAG With RTCK
        2. 5.10.7.2 TPIU
          1. 5.10.7.2.1 TPIU PLL DDR Mode
  6. 6Detailed Description
    1. 6.1  Description
    2. 6.2  Functional Block Diagram
    3. 6.3  MPU
    4. 6.4  DSP Subsystem
    5. 6.5  ISS
    6. 6.6  IVA
    7. 6.7  EVE
    8. 6.8  IPU
    9. 6.9  VPE
    10. 6.10 GPU
    11. 6.11 ATL Overview
    12. 6.12 Memory Subsystem
      1. 6.12.1 EMIF
      2. 6.12.2 GPMC
      3. 6.12.3 ELM
      4. 6.12.4 OCMC
    13. 6.13 Interprocessor Communication
      1. 6.13.1 Mailbox
      2. 6.13.2 Spinlock
    14. 6.14 Interrupt Controller
    15. 6.15 EDMA
    16. 6.16 Peripherals
      1. 6.16.1  VIP
      2. 6.16.2  DSS
      3. 6.16.3  Timers
      4. 6.16.4  I2C
      5. 6.16.5  HDQ1W
      6. 6.16.6  UART
        1. 6.16.6.1 UART Features
        2. 6.16.6.2 IrDA Features
        3. 6.16.6.3 CIR Features
      7. 6.16.7  McSPI
      8. 6.16.8  QSPI
      9. 6.16.9  McASP
      10. 6.16.10 USB
      11. 6.16.11 SATA
      12. 6.16.12 PCIe
      13. 6.16.13 CAN
      14. 6.16.14 GMAC_SW
      15. 6.16.15 MLB
      16. 6.16.16 eMMC/SD/SDIO
      17. 6.16.17 GPIO
      18. 6.16.18 ePWM
      19. 6.16.19 eCAP
      20. 6.16.20 eQEP
    17. 6.17 On-Chip Debug
  7. 7Applications, Implementation, and Layout
    1. 7.1 Introduction
      1. 7.1.1 Initial Requirements and Guidelines
    2. 7.2 Power Optimizations
      1. 7.2.1 Step 1: PCB Stack-up
      2. 7.2.2 Step 2: Physical Placement
      3. 7.2.3 Step 3: Static Analysis
        1. 7.2.3.1 PDN Resistance and IR Drop
      4. 7.2.4 Step 4: Frequency Analysis
      5. 7.2.5 System ESD Generic Guidelines
        1. 7.2.5.1 System ESD Generic PCB Guideline
        2. 7.2.5.2 Miscellaneous EMC Guidelines to Mitigate ESD Immunity
      6. 7.2.6 EMI / EMC Issues Prevention
        1. 7.2.6.1 Signal Bandwidth
        2. 7.2.6.2 Signal Routing
          1. 7.2.6.2.1 Signal Routing—Sensitive Signals and Shielding
          2. 7.2.6.2.2 Signal Routing—Outer Layer Routing
        3. 7.2.6.3 Ground Guidelines
          1. 7.2.6.3.1 PCB Outer Layers
          2. 7.2.6.3.2 Metallic Frames
          3. 7.2.6.3.3 Connectors
          4. 7.2.6.3.4 Guard Ring on PCB Edges
          5. 7.2.6.3.5 Analog and Digital Ground
    3. 7.3 Core Power Domains
      1. 7.3.1 General Constraints and Theory
      2. 7.3.2 Voltage Decoupling
      3. 7.3.3 Static PDN Analysis
      4. 7.3.4 Dynamic PDN Analysis
      5. 7.3.5 Power Supply Mapping
      6. 7.3.6 DPLL Voltage Requirement
      7. 7.3.7 Loss of Input Power Event
      8. 7.3.8 Example PCB Design
        1. 7.3.8.1 Example Stack-up
        2. 7.3.8.2 vdd_mpu Example Analysis
    4. 7.4 Single-Ended Interfaces
      1. 7.4.1 General Routing Guidelines
      2. 7.4.2 QSPI Board Design and Layout Guidelines
    5. 7.5 Differential Interfaces
      1. 7.5.1 General Routing Guidelines
      2. 7.5.2 USB 2.0 Board Design and Layout Guidelines
        1. 7.5.2.1 Background
        2. 7.5.2.2 USB PHY Layout Guide
          1. 7.5.2.2.1 General Routing and Placement
          2. 7.5.2.2.2 Specific Guidelines for USB PHY Layout
            1. 7.5.2.2.2.1  Analog, PLL, and Digital Power Supply Filtering
            2. 7.5.2.2.2.2  Analog, Digital, and PLL Partitioning
            3. 7.5.2.2.2.3  Board Stackup
            4. 7.5.2.2.2.4  Cable Connector Socket
            5. 7.5.2.2.2.5  Clock Routings
            6. 7.5.2.2.2.6  Crystals/Oscillator
            7. 7.5.2.2.2.7  DP/DM Trace
            8. 7.5.2.2.2.8  DP/DM Vias
            9. 7.5.2.2.2.9  Image Planes
            10. 7.5.2.2.2.10 JTAG Interface
            11. 7.5.2.2.2.11 Power Regulators
        3. 7.5.2.3 Electrostatic Discharge (ESD)
          1. 7.5.2.3.1 IEC ESD Stressing Test
            1. 7.5.2.3.1.1 Test Mode
            2. 7.5.2.3.1.2 Air Discharge Mode
            3. 7.5.2.3.1.3 Test Type
          2. 7.5.2.3.2 TI Component Level IEC ESD Test
          3. 7.5.2.3.3 Construction of a Custom USB Connector
          4. 7.5.2.3.4 ESD Protection System Design Consideration
        4. 7.5.2.4 References
      3. 7.5.3 USB 3.0 Board Design and Layout Guidelines
        1. 7.5.3.1 USB 3.0 interface introduction
        2. 7.5.3.2 USB 3.0 General routing rules
      4. 7.5.4 HDMI Board Design and Layout Guidelines
        1. 7.5.4.1 HDMI Interface Schematic
        2. 7.5.4.2 TMDS General Routing Guidelines
        3. 7.5.4.3 TPD5S115
        4. 7.5.4.4 HDMI ESD Protection Device (Required)
        5. 7.5.4.5 PCB Stackup Specifications
        6. 7.5.4.6 Grounding
      5. 7.5.5 SATA Board Design and Layout Guidelines
        1. 7.5.5.1 SATA Interface Schematic
        2. 7.5.5.2 Compatible SATA Components and Modes
        3. 7.5.5.3 PCB Stackup Specifications
        4. 7.5.5.4 Routing Specifications
      6. 7.5.6 PCIe Board Design and Layout Guidelines
        1. 7.5.6.1 PCIe Connections and Interface Compliance
          1. 7.5.6.1.1 Coupling Capacitors
          2. 7.5.6.1.2 Polarity Inversion
        2. 7.5.6.2 Non-standard PCIe connections
          1. 7.5.6.2.1 PCB Stackup Specifications
          2. 7.5.6.2.2 Routing Specifications
            1. 7.5.6.2.2.1 Impedance
            2. 7.5.6.2.2.2 Differential Coupling
            3. 7.5.6.2.2.3 Pair Length Matching
        3. 7.5.6.3 LJCB_REFN/P Connections
    6. 7.6 Clock Routing Guidelines
      1. 7.6.1 32-kHz Oscillator Routing
      2. 7.6.2 Oscillator Ground Connection
    7. 7.7 DDR2/DDR3 Board Design and Layout Guidelines
      1. 7.7.1 DDR2/DDR3 General Board Layout Guidelines
      2. 7.7.2 DDR2 Board Design and Layout Guidelines
        1. 7.7.2.1 Board Designs
        2. 7.7.2.2 DDR2 Interface
          1. 7.7.2.2.1  DDR2 Interface Schematic
          2. 7.7.2.2.2  Compatible JEDEC DDR2 Devices
          3. 7.7.2.2.3  PCB Stackup
          4. 7.7.2.2.4  Placement
          5. 7.7.2.2.5  DDR2 Keepout Region
          6. 7.7.2.2.6  Bulk Bypass Capacitors
          7. 7.7.2.2.7  High-Speed Bypass Capacitors
          8. 7.7.2.2.8  Net Classes
          9. 7.7.2.2.9  DDR2 Signal Termination
          10. 7.7.2.2.10 VREF Routing
        3. 7.7.2.3 DDR2 CK and ADDR_CTRL Routing
      3. 7.7.3 DDR3 Board Design and Layout Guidelines
        1. 7.7.3.1  Board Designs
        2. 7.7.3.2  DDR3 EMIF
        3. 7.7.3.3  DDR3 Device Combinations
        4. 7.7.3.4  DDR3 Interface Schematic
          1. 7.7.3.4.1 32-Bit DDR3 Interface
          2. 7.7.3.4.2 16-Bit DDR3 Interface
        5. 7.7.3.5  Compatible JEDEC DDR3 Devices
        6. 7.7.3.6  PCB Stackup
        7. 7.7.3.7  Placement
        8. 7.7.3.8  DDR3 Keepout Region
        9. 7.7.3.9  Bulk Bypass Capacitors
        10. 7.7.3.10 High-Speed Bypass Capacitors
          1. 7.7.3.10.1 Return Current Bypass Capacitors
        11. 7.7.3.11 Net Classes
        12. 7.7.3.12 DDR3 Signal Termination
        13. 7.7.3.13 VREF_DDR Routing
        14. 7.7.3.14 VTT
        15. 7.7.3.15 CK and ADDR_CTRL Topologies and Routing Definition
          1. 7.7.3.15.1 Four DDR3 Devices
            1. 7.7.3.15.1.1 CK and ADDR_CTRL Topologies, Four DDR3 Devices
            2. 7.7.3.15.1.2 CK and ADDR_CTRL Routing, Four DDR3 Devices
          2. 7.7.3.15.2 Two DDR3 Devices
            1. 7.7.3.15.2.1 CK and ADDR_CTRL Topologies, Two DDR3 Devices
            2. 7.7.3.15.2.2 CK and ADDR_CTRL Routing, Two DDR3 Devices
          3. 7.7.3.15.3 One DDR3 Device
            1. 7.7.3.15.3.1 CK and ADDR_CTRL Topologies, One DDR3 Device
            2. 7.7.3.15.3.2 CK and ADDR/CTRL Routing, One DDR3 Device
        16. 7.7.3.16 Data Topologies and Routing Definition
          1. 7.7.3.16.1 DQS and DQ/DM Topologies, Any Number of Allowed DDR3 Devices
          2. 7.7.3.16.2 DQS and DQ/DM Routing, Any Number of Allowed DDR3 Devices
        17. 7.7.3.17 Routing Specification
          1. 7.7.3.17.1 CK and ADDR_CTRL Routing Specification
          2. 7.7.3.17.2 DQS and DQ Routing Specification
  8. 8Device and Documentation Support
    1. 8.1  Device Nomenclature
      1. 8.1.1 Standard Package Symbolization
      2. 8.1.2 Device Naming Convention
    2. 8.2  Tools and Software
    3. 8.3  Documentation Support
      1. 8.3.1 FCC Warning
      2. 8.3.2 Information About Cautions and Warnings
    4. 8.4  Receiving Notification of Documentation Updates
    5. 8.5  Related Links
    6. 8.6  Community Resources
    7. 8.7  Trademarks
    8. 8.8  Electrostatic Discharge Caution
    9. 8.9  Export Control Notice
    10. 8.10 Glossary
  9. 9Mechanical Packaging and Orderable Information
    1. 9.1 Mechanical Data

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • ABZ|760
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.5.4.2 TMDS General Routing Guidelines

The TMDS signals are high speed differential pairs. Care must be taken in the PCB layout of these signals to ensure good signal integrity.

The TMDS differential signal traces must be routed to achieve 100 Ω (+/- 10%) differential impedance and 60 Ω (+/-10%) single ended impedance. Single ended impedance control is required because differential signals can’t be closely coupled on PCBs and therefore single ended impedance becomes important.

These impedances are impacted by trace width, trace spacing, distance to reference planes, and dielectric material. Verify with a PCB design tool that the trace geometry for both data signal pairs results in as close to 60 Ω impedance traces as possible. For best accuracy, work with your PCB fabricator to ensure this impedance is met.

In general, closely coupled differential signal traces are not an advantage on PCBs. When differential signals are closely coupled, tight spacing and width control is necessary. Very small width and spacing variations affect impedance dramatically, so tight impedance control can be more problematic to maintain in production.

Loosely coupled PCB differential signals make impedance control much easier. Wider traces and spacing make obstacle avoidance easier, and trace width variations don’t affect impedance as much, therefore it’s easier to maintain accurate impedance over the length of the signal. The wider traces also show reduced skin effect and therefore often result in better signal integrity.

Some general routing guidelines regarding TMDS:

  • Avoid crossing splits reference plane(s).
  • Shorter trace length is preferred.
  • Distance between common mode filter (CMF) and ESD protection device should be as short as possible
  • Distance between ESD protection device and HDMI connector should be as short as possible.

Table 7-14 shows the routing specifications for the TMDS signals.

Table 7-14 TMDS Routing Specifications

PARAMETER MIN TYP MAX UNIT
Device balls to HDMI header trace length 4000 Mils
Skew within a differential pair 3 5 Mils
Number of stubs allowed on TMDS traces 0 stubs
TMDS pair differential impedance 90 100 110 Ω
TMDS single-ended impedance 54 60 66 Ω
Number of vias on each TMDS trace 0 Vias
TMDS differential pair to any other trace spacing (1)(2)(3) 2×DS 3xDS Mils
Number of ground plane cuts allowed within HDMI routing region (except for specific ground carving as explained in this document) 0 Cuts
Number of layers between HDMI routing region and reference ground plane 0 Layers
PCB trace width 4.4 Mils
  1. DS = differential spacing of the traces.
  2. Exceptions may be necessary in the SoC package BGA area.
  3. GND guard-bands may be closer, but should not be allowed to affect the impedance of the differential pair routing. GND guard-bands to isolate HDMI differential pairs from all other signals is recommended.

Table 7-15 TDMS Routing Recommendations

Item Description Reason
ESD part number TPD1E05U06 Minimize capacitance (0.42pF)
Carve Ground Carve GND underneath ESD and CMF Minimize capacitance under ESD and CMF
Round pads Reduce pad size and round the corners of the pads for the ESD and CMF components Minimize capacitance
Routing layer Route all signals only on the same layer as SoC Minimize reflection loss

Figure 7-44presents an example layout, demonstrating the “carve GND” concept.

DRA75P DRA74P SPRS85x_PCB_HDMI_3.gifFigure 7-44 HDMI Example “carve GND” layout