SPRS950F December   2015  – May 2019 DRA745 , DRA746 , DRA750 , DRA756

PRODUCTION DATA.  

  1. 1 Device Overview
    1. 1.1 Features
    2. 1.2 Applications
    3. 1.3 Description
    4. 1.4 Functional Block Diagram
  2. 2 Revision History
  3. 3 Device Comparison
    1. 3.1 Related Products
  4. 4 Terminal Configuration and Functions
    1. 4.1 Terminal Assignment
      1. 4.1.1 Unused Balls Connection Requirements
    2. 4.2 Ball Characteristics
    3. 4.3 Multiplexing Characteristics
    4. 4.4 Signal Descriptions
      1. 4.4.1  Video Input Ports (VIP)
      2. 4.4.2  Display Subsystem – Video Output Ports
      3. 4.4.3  Display Subsystem – High-Definition Multimedia Interface (HDMI)
      4. 4.4.4  External Memory Interface (EMIF)
      5. 4.4.5  General-Purpose Memory Controller (GPMC)
      6. 4.4.6  Timers
      7. 4.4.7  Inter-Integrated Circuit Interface (I2C)
      8. 4.4.8  HDQ / 1-Wire Interface (HDQ1W)
      9. 4.4.9  Universal Asynchronous Receiver Transmitter (UART)
      10. 4.4.10 Multichannel Serial Peripheral Interface (McSPI)
      11. 4.4.11 Quad Serial Peripheral Interface (QSPI)
      12. 4.4.12 Multichannel Audio Serial Port (McASP)
      13. 4.4.13 Universal Serial Bus (USB)
      14. 4.4.14 SATA
      15. 4.4.15 Peripheral Component Interconnect Express (PCIe)
      16. 4.4.16 Controller Area Network Interface (DCAN)
      17. 4.4.17 Ethernet Interface (GMAC_SW)
      18. 4.4.18 Media Local Bus (MLB) Interface
      19. 4.4.19 eMMC/SD/SDIO
      20. 4.4.20 General-Purpose Interface (GPIO)
      21. 4.4.21 Keyboard controller (KBD)
      22. 4.4.22 Pulse Width Modulation (PWM) Interface
      23. 4.4.23 Audio Tracking Logic (ATL)
      24. 4.4.24 Test Interfaces
      25. 4.4.25 System and Miscellaneous
        1. 4.4.25.1 Sysboot
        2. 4.4.25.2 Power, Reset, and Clock Management (PRCM)
        3. 4.4.25.3 Real Time Clock (RTC) Interface
        4. 4.4.25.4 System Direct Memory Access (SDMA)
        5. 4.4.25.5 Interrupt Controllers (INTC)
        6. 4.4.25.6 Observability
      26. 4.4.26 Power Supplies
  5. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Power on Hour (POH) Limits
    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. 5.7.1  LVCMOS DDR DC Electrical Characteristics
      2. 5.7.2  HDMIPHY DC Electrical Characteristics
      3. 5.7.3  Dual Voltage LVCMOS I2C DC Electrical Characteristics
      4. 5.7.4  IQ1833 Buffers DC Electrical Characteristics
      5. 5.7.5  IHHV1833 Buffers DC Electrical Characteristics
      6. 5.7.6  LVCMOS OSC Buffers DC Electrical Characteristics
      7. 5.7.7  ILVDS18 Buffers DC Electrical Characteristics
      8. 5.7.8  BMLB18 Buffers DC Electrical Characteristics
      9. 5.7.9  BC1833IHHV Buffers DC Electrical Characteristics
      10. 5.7.10 USBPHY DC Electrical Characteristics
      11. 5.7.11 Dual Voltage SDIO1833 DC Electrical Characteristics
      12. 5.7.12 Dual Voltage LVCMOS DC Electrical Characteristics
      13. 5.7.13 SATAPHY DC Electrical Characteristics
      14. 5.7.14 PCIEPHY DC Electrical Characteristics
    8. 5.8 Thermal Resistance Characteristics
      1. 5.8.1 Package Thermal Characteristics
    9. 5.9 Power Supply Sequences
  6. 6 Clock Specifications
    1. 6.1 Input Clock Specifications
      1. 6.1.1 Input Clock Requirements
      2. 6.1.2 System Oscillator OSC0 Input Clock
        1. 6.1.2.1 OSC0 External Crystal
        2. 6.1.2.2 OSC0 Input Clock
      3. 6.1.3 Auxiliary Oscillator OSC1 Input Clock
        1. 6.1.3.1 OSC1 External Crystal
        2. 6.1.3.2 OSC1 Input Clock
      4. 6.1.4 RTC Oscillator Input Clock
        1. 6.1.4.1 RTC Oscillator External Crystal
        2. 6.1.4.2 RTC Oscillator Input Clock
    2. 6.2 RC On-die Oscillator Clock
    3. 6.3 DPLLs, DLLs Specifications
      1. 6.3.1 DPLL Characteristics
      2. 6.3.2 DLL Characteristics
      3. 6.3.3 DPLL and DLL Noise Isolation
  7. 7 Timing Requirements and Switching Characteristics
    1. 7.1  Timing Test Conditions
    2. 7.2  Interface Clock Specifications
      1. 7.2.1 Interface Clock Terminology
      2. 7.2.2 Interface Clock Frequency
    3. 7.3  Timing Parameters and Information
      1. 7.3.1 Parameter Information
        1. 7.3.1.1 1.8V and 3.3V Signal Transition Levels
        2. 7.3.1.2 1.8V and 3.3V Signal Transition Rates
        3. 7.3.1.3 Timing Parameters and Board Routing Analysis
    4. 7.4  Recommended Clock and Control Signal Transition Behavior
    5. 7.5  Virtual and Manual I/O Timing Modes
    6. 7.6  Video Input Ports (VIP)
    7. 7.7  Display Subsystem – Video Output Ports
    8. 7.8  Display Subsystem – High-Definition Multimedia Interface (HDMI)
    9. 7.9  External Memory Interface (EMIF)
    10. 7.10 General-Purpose Memory Controller (GPMC)
      1. 7.10.1 GPMC/NOR Flash Interface Synchronous Timing
      2. 7.10.2 GPMC/NOR Flash Interface Asynchronous Timing
      3. 7.10.3 GPMC/NAND Flash Interface Asynchronous Timing
    11. 7.11 Timers
    12. 7.12 Inter-Integrated Circuit Interface (I2C)
      1. Table 7-34 Timing Requirements for I2C Input Timings
      2. Table 7-35 Timing Requirements for I2C HS-Mode (I2C3/4/5 Only)
      3. Table 7-36 Switching Characteristics Over Recommended Operating Conditions for I2C Output Timings
    13. 7.13 HDQ / 1-Wire Interface (HDQ1W)
      1. 7.13.1 HDQ / 1-Wire — HDQ Mode
      2. 7.13.2 HDQ/1-Wire—1-Wire Mode
    14. 7.14 Universal Asynchronous Receiver Transmitter (UART)
      1. Table 7-41 Timing Requirements for UART
      2. Table 7-42 Switching Characteristics Over Recommended Operating Conditions for UART
    15. 7.15 Multichannel Serial Peripheral Interface (McSPI)
    16. 7.16 Quad Serial Peripheral Interface (QSPI)
    17. 7.17 Multichannel Audio Serial Port (McASP)
      1. Table 7-49 Timing Requirements for McASP1
      2. Table 7-50 Timing Requirements for McASP2
      3. Table 7-51 Timing Requirements for McASP3/4/5/6/7/8
      4. Table 7-52 Switching Characteristics Over Recommended Operating Conditions for McASP1
      5. Table 7-53 Switching Characteristics Over Recommended Operating Conditions for McASP2
      6. Table 7-54 Switching Characteristics Over Recommended Operating Conditions for McASP3/4/5/6/7/8
    18. 7.18 Universal Serial Bus (USB)
      1. 7.18.1 USB1 DRD PHY
      2. 7.18.2 USB2 PHY
      3. 7.18.3 USB3 and USB4 DRD ULPI—SDR—Slave Mode—12-pin Mode
    19. 7.19 Serial Advanced Technology Attachment (SATA)
    20. 7.20 Peripheral Component Interconnect Express (PCIe)
    21. 7.21 Controller Area Network Interface (DCAN)
      1. Table 7-69 Timing Requirements for DCANx Receive
      2. Table 7-70 Switching Characteristics Over Recommended Operating Conditions for DCANx Transmit
    22. 7.22 Ethernet Interface (GMAC_SW)
      1. 7.22.1 GMAC MII Timings
        1. Table 7-71 Timing Requirements for miin_rxclk - MII Operation
        2. Table 7-72 Timing Requirements for miin_txclk - MII Operation
        3. Table 7-73 Timing Requirements for GMAC MIIn Receive 10/100 Mbit/s
        4. Table 7-74 Switching Characteristics Over Recommended Operating Conditions for GMAC MIIn Transmit 10/100 Mbits/s
      2. 7.22.2 GMAC MDIO Interface Timings
      3. 7.22.3 GMAC RMII Timings
        1. Table 7-79 Timing Requirements for GMAC REF_CLK - RMII Operation
        2. Table 7-80 Timing Requirements for GMAC RMIIn Receive
        3. Table 7-81 Switching Characteristics Over Recommended Operating Conditions for GMAC REF_CLK - RMII Operation
        4. Table 7-82 Switching Characteristics Over Recommended Operating Conditions for GMAC RMIIn Transmit 10/100 Mbits/s
      4. 7.22.4 GMAC RGMII Timings
        1. Table 7-86 Timing Requirements for rgmiin_rxc - RGMIIn Operation
        2. Table 7-87 Timing Requirements for GMAC RGMIIn Input Receive for 10/100/1000 Mbps
        3. Table 7-88 Switching Characteristics Over Recommended Operating Conditions for rgmiin_txctl - RGMIIn Operation for 10/100/1000 Mbit/s
        4. Table 7-89 Switching Characteristics for GMAC RGMIIn Output Transmit for 10/100/1000 Mbps
    23. 7.23 Media Local Bus (MLB) interface
    24. 7.24 eMMC/SD/SDIO
      1. 7.24.1 MMC1—SD Card Interface
        1. 7.24.1.1 Default speed, 4-bit data, SDR, half-cycle
        2. 7.24.1.2 High speed, 4-bit data, SDR, half-cycle
        3. 7.24.1.3 SDR12, 4-bit data, half-cycle
        4. 7.24.1.4 SDR25, 4-bit data, half-cycle
        5. 7.24.1.5 UHS-I SDR50, 4-bit data, half-cycle
        6. 7.24.1.6 UHS-I SDR104, 4-bit data, half-cycle
        7. 7.24.1.7 UHS-I DDR50, 4-bit data
      2. 7.24.2 MMC2 — eMMC
        1. 7.24.2.1 Standard JC64 SDR, 8-bit data, half cycle
        2. 7.24.2.2 High-speed JC64 SDR, 8-bit data, half cycle
        3. 7.24.2.3 High-speed HS200 JC64 SDR, 8-bit data, half cycle
        4. 7.24.2.4 High-speed JC64 DDR, 8-bit data
      3. 7.24.3 MMC3 and MMC4—SDIO/SD
        1. 7.24.3.1 MMC3 and MMC4, SD Default Speed
        2. 7.24.3.2 MMC3 and MMC4, SD High Speed
        3. 7.24.3.3 MMC3 and MMC4, SD and SDIO SDR12 Mode
        4. 7.24.3.4 MMC3 and MMC4, SD SDR25 Mode
        5. 7.24.3.5 MMC3 SDIO High-Speed UHS-I SDR50 Mode, Half Cycle
    25. 7.25 General-Purpose Interface (GPIO)
    26. 7.26 Audio Tracking Logic (ATL)
      1. 7.26.1 ATL Electrical Data/Timing
        1. Table 7-145 Switching Characteristics Over Recommended Operating Conditions for ATL_CLKOUTx
    27. 7.27 System and Miscellaneous interfaces
    28. 7.28 Test Interfaces
      1. 7.28.1 IEEE 1149.1 Standard-Test-Access Port (JTAG)
        1. 7.28.1.1 JTAG Electrical Data/Timing
          1. Table 7-146 Timing Requirements for IEEE 1149.1 JTAG
          2. Table 7-147 Switching Characteristics Over Recommended Operating Conditions for IEEE 1149.1 JTAG
          3. Table 7-148 Timing Requirements for IEEE 1149.1 JTAG With RTCK
          4. Table 7-149 Switching Characteristics Over Recommended Operating Conditions for IEEE 1149.1 JTAG With RTCK
      2. 7.28.2 Trace Port Interface Unit (TPIU)
        1. 7.28.2.1 TPIU PLL DDR Mode
  8. 8 Applications, Implementation, and Layout
    1. 8.1 Introduction
      1. 8.1.1 Initial Requirements and Guidelines
    2. 8.2 Power Optimizations
      1. 8.2.1 Step 1: PCB Stack-up
      2. 8.2.2 Step 2: Physical Placement
      3. 8.2.3 Step 3: Static Analysis
        1. 8.2.3.1 PDN Resistance and IR Drop
      4. 8.2.4 Step 4: Frequency Analysis
      5. 8.2.5 System ESD Generic Guidelines
        1. 8.2.5.1 System ESD Generic PCB Guideline
        2. 8.2.5.2 Miscellaneous EMC Guidelines to Mitigate ESD Immunity
      6. 8.2.6 EMI / EMC Issues Prevention
        1. 8.2.6.1 Signal Bandwidth
        2. 8.2.6.2 Signal Routing
          1. 8.2.6.2.1 Signal Routing—Sensitive Signals and Shielding
          2. 8.2.6.2.2 Signal Routing—Outer Layer Routing
        3. 8.2.6.3 Ground Guidelines
          1. 8.2.6.3.1 PCB Outer Layers
          2. 8.2.6.3.2 Metallic Frames
          3. 8.2.6.3.3 Connectors
          4. 8.2.6.3.4 Guard Ring on PCB Edges
          5. 8.2.6.3.5 Analog and Digital Ground
    3. 8.3 Core Power Domains
      1. 8.3.1 General Constraints and Theory
      2. 8.3.2 Voltage Decoupling
      3. 8.3.3 Static PDN Analysis
      4. 8.3.4 Dynamic PDN Analysis
      5. 8.3.5 Power Supply Mapping
      6. 8.3.6 DPLL Voltage Requirement
      7. 8.3.7 Loss of Input Power Event
      8. 8.3.8 Example PCB Design
        1. 8.3.8.1 Example Stack-up
        2. 8.3.8.2 vdd_mpu Example Analysis
    4. 8.4 Single-Ended Interfaces
      1. 8.4.1 General Routing Guidelines
      2. 8.4.2 QSPI Board Design and Layout Guidelines
    5. 8.5 Differential Interfaces
      1. 8.5.1 General Routing Guidelines
      2. 8.5.2 USB 2.0 Board Design and Layout Guidelines
        1. 8.5.2.1 Background
        2. 8.5.2.2 USB PHY Layout Guide
          1. 8.5.2.2.1 General Routing and Placement
          2. 8.5.2.2.2 Specific Guidelines for USB PHY Layout
            1. 8.5.2.2.2.1  Analog, PLL, and Digital Power Supply Filtering
            2. 8.5.2.2.2.2  Analog, Digital, and PLL Partitioning
            3. 8.5.2.2.2.3  Board Stackup
            4. 8.5.2.2.2.4  Cable Connector Socket
            5. 8.5.2.2.2.5  Clock Routings
            6. 8.5.2.2.2.6  Crystals/Oscillator
            7. 8.5.2.2.2.7  DP/DM Trace
            8. 8.5.2.2.2.8  DP/DM Vias
            9. 8.5.2.2.2.9  Image Planes
            10. 8.5.2.2.2.10 JTAG Interface
            11. 8.5.2.2.2.11 Power Regulators
        3. 8.5.2.3 Electrostatic Discharge (ESD)
          1. 8.5.2.3.1 IEC ESD Stressing Test
            1. 8.5.2.3.1.1 Test Mode
            2. 8.5.2.3.1.2 Air Discharge Mode
            3. 8.5.2.3.1.3 Test Type
          2. 8.5.2.3.2 TI Component Level IEC ESD Test
          3. 8.5.2.3.3 Construction of a Custom USB Connector
          4. 8.5.2.3.4 ESD Protection System Design Consideration
        4. 8.5.2.4 References
      3. 8.5.3 USB 3.0 Board Design and Layout Guidelines
        1. 8.5.3.1 USB 3.0 interface introduction
        2. 8.5.3.2 USB 3.0 General routing rules
      4. 8.5.4 HDMI Board Design and Layout Guidelines
        1. 8.5.4.1 HDMI Interface Schematic
        2. 8.5.4.2 TMDS General Routing Guidelines
        3. 8.5.4.3 TPD5S115
        4. 8.5.4.4 HDMI ESD Protection Device (Required)
        5. 8.5.4.5 PCB Stackup Specifications
        6. 8.5.4.6 Grounding
      5. 8.5.5 SATA Board Design and Layout Guidelines
        1. 8.5.5.1 SATA Interface Schematic
        2. 8.5.5.2 Compatible SATA Components and Modes
        3. 8.5.5.3 PCB Stackup Specifications
        4. 8.5.5.4 Routing Specifications
      6. 8.5.6 PCIe Board Design and Layout Guidelines
        1. 8.5.6.1 PCIe Connections and Interface Compliance
          1. 8.5.6.1.1 Coupling Capacitors
          2. 8.5.6.1.2 Polarity Inversion
        2. 8.5.6.2 Non-standard PCIe connections
          1. 8.5.6.2.1 PCB Stackup Specifications
          2. 8.5.6.2.2 Routing Specifications
            1. 8.5.6.2.2.1 Impedance
            2. 8.5.6.2.2.2 Differential Coupling
            3. 8.5.6.2.2.3 Pair Length Matching
        3. 8.5.6.3 LJCB_REFN/P Connections
    6. 8.6 Clock Routing Guidelines
      1. 8.6.1 32-kHz Oscillator Routing
      2. 8.6.2 Oscillator Ground Connection
    7. 8.7 DDR2/DDR3 Board Design and Layout Guidelines
      1. 8.7.1 DDR2/DDR3 General Board Layout Guidelines
      2. 8.7.2 DDR2 Board Design and Layout Guidelines
        1. 8.7.2.1 Board Designs
        2. 8.7.2.2 DDR2 Interface
          1. 8.7.2.2.1  DDR2 Interface Schematic
          2. 8.7.2.2.2  Compatible JEDEC DDR2 Devices
          3. 8.7.2.2.3  PCB Stackup
          4. 8.7.2.2.4  Placement
          5. 8.7.2.2.5  DDR2 Keepout Region
          6. 8.7.2.2.6  Bulk Bypass Capacitors
          7. 8.7.2.2.7  High-Speed Bypass Capacitors
          8. 8.7.2.2.8  Net Classes
          9. 8.7.2.2.9  DDR2 Signal Termination
          10. 8.7.2.2.10 VREF Routing
        3. 8.7.2.3 DDR2 CK and ADDR_CTRL Routing
      3. 8.7.3 DDR3 Board Design and Layout Guidelines
        1. 8.7.3.1  Board Designs
          1. 8.7.3.1.1 DDR3 versus DDR2
        2. 8.7.3.2  DDR3 EMIFs
        3. 8.7.3.3  DDR3 Device Combinations
        4. 8.7.3.4  DDR3 Interface Schematic
          1. 8.7.3.4.1 32-Bit DDR3 Interface
          2. 8.7.3.4.2 16-Bit DDR3 Interface
        5. 8.7.3.5  Compatible JEDEC DDR3 Devices
        6. 8.7.3.6  PCB Stackup
        7. 8.7.3.7  Placement
        8. 8.7.3.8  DDR3 Keepout Region
        9. 8.7.3.9  Bulk Bypass Capacitors
        10. 8.7.3.10 High-Speed Bypass Capacitors
          1. 8.7.3.10.1 Return Current Bypass Capacitors
        11. 8.7.3.11 Net Classes
        12. 8.7.3.12 DDR3 Signal Termination
        13. 8.7.3.13 VREF_DDR Routing
        14. 8.7.3.14 VTT
        15. 8.7.3.15 CK and ADDR_CTRL Topologies and Routing Definition
          1. 8.7.3.15.1 Four DDR3 Devices
            1. 8.7.3.15.1.1 CK and ADDR_CTRL Topologies, Four DDR3 Devices
            2. 8.7.3.15.1.2 CK and ADDR_CTRL Routing, Four DDR3 Devices
          2. 8.7.3.15.2 Two DDR3 Devices
            1. 8.7.3.15.2.1 CK and ADDR_CTRL Topologies, Two DDR3 Devices
            2. 8.7.3.15.2.2 CK and ADDR_CTRL Routing, Two DDR3 Devices
          3. 8.7.3.15.3 One DDR3 Device
            1. 8.7.3.15.3.1 CK and ADDR_CTRL Topologies, One DDR3 Device
            2. 8.7.3.15.3.2 CK and ADDR/CTRL Routing, One DDR3 Device
        16. 8.7.3.16 Data Topologies and Routing Definition
          1. 8.7.3.16.1 DQS and DQ/DM Topologies, Any Number of Allowed DDR3 Devices
          2. 8.7.3.16.2 DQS and DQ/DM Routing, Any Number of Allowed DDR3 Devices
        17. 8.7.3.17 Routing Specification
          1. 8.7.3.17.1 CK and ADDR_CTRL Routing Specification
          2. 8.7.3.17.2 DQS and DQ Routing Specification
  9. 9 Device and Documentation Support
    1. 9.1 Device Nomenclature
      1. 9.1.1 Standard Package Symbolization
      2. 9.1.2 Device Naming Convention
    2. 9.2 Tools and Software
    3. 9.3 Documentation Support
    4. 9.4 Related Links
    5. 9.5 Community Resources
    6. 9.6 Trademarks
    7. 9.7 Electrostatic Discharge Caution
    8. 9.8 Glossary
  10. 10Mechanical, Packaging, and Orderable Information
    1. 10.1 Packaging Information

Package Options

Refer to the PDF data sheet for device specific package drawings

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

8.3.8.2 vdd_mpu Example Analysis

Maximum acceptable PCB resistance (Reff) between the PMIC and Processor input power balls should not exceed 10mΩ.

Maximum decoupling capacitance loop inductance (LL) between Processor input power balls and decoupling capacitances should not exceed 2.0nH (ESL NOT included)

Impedance target for key frequency of interest between Processor input power balls and PMIC’s SMPS output power balls should not exceed 57mΩ at 20MHz.

Table 8-7 Example PCB vdd_mpu PI Analysis Summary

Parameter Recommendation Example PCB
Processor OPP High
Clocking Rate 1.5 GHz
Voltage Level 1.22V 1.22V
Max Current Draw 5.12 A 5.12 A
Max Effective Resistance: Power Inductor Segment Total Reff 10mΩ 9.0mΩ
Max Loop Inductance 2.0nH 1.0 – 1.4nH
Impedance Target 57mΩ F<20Mhz 57mΩ F<20Mhz

Figure 8-21, Figure 8-22, Figure 8-23, and Figure 8-24 show a PCB layout example and the resulting PI analysis results.

DRA756 DRA755 DRA754 DRA752 DRA751 DRA750 DRA746 DRA745 DRA744 VAYU_PCB_CPD_1.gifFigure 8-21 vdd_mpu Simplified SCH Diagram
DRA756 DRA755 DRA754 DRA752 DRA751 DRA750 DRA746 DRA745 DRA744 VAYU_PCB_CPD_2.gifFigure 8-22 vdd_mpu routing [Top Layer]
DRA756 DRA755 DRA754 DRA752 DRA751 DRA750 DRA746 DRA745 DRA744 VAYU_PCB_CPD_3.gifFigure 8-23 vdd_mpu routing [Internal Power Plane #2]
DRA756 DRA755 DRA754 DRA752 DRA751 DRA750 DRA746 DRA745 DRA744 VAYU_PCB_CPD_4.gifFigure 8-24 vdd_mpu routing and cap placements [Bottom Layer]

Table 8-8 PCB Etch Resistance Breakdown - From PMIC Source to Device Load

Net[from] Component [from]: Net[to] Component [to]: Etch Resistance (Ω) % of Total Etch Resistance
SW1 L17 SW1 U45 0,001038 13%
SW2 L15 SW2 U45 0,000898 12%
SW3 L13 SW3 U45 0,000861 11%
SW1 L17 SMPS_1_2_3 R181 0,000696 9%
SW2 L15 SMPS_1_2_3 R181 0,000541 7%
SW3 L13 SMPS_1_2_3 R181 0,000526 7%
vdd_mpu R181 vdd_mpu U52 0,006311 78%
vdd_mpu R181 vdd_mpu U52 0,006311 81%
vdd_mpu R181 vdd_mpu U52 0,006311 82%
Total Etch Resistance from SW1 = 0,008045 100%
Total Etch Resistance from SW2 = 0,00775 100%
Total Etch Resistance from SW3 = 0,007698 100%
Max Value = 0,008045

Table 8-9 PCB Etch Resistance Breakdown - From Power Inductor to Device Load

Net[from] Component [from]: Net[to] Component [to]: Etch Resistance (Ω) % of Total Etch Resistance
SMPS_1_2_3 L17 SMPS_1_2_3 R181 0,000696 10%
SMPS_1_2_3 L15 SMPS_1_2_3 R181 0,000541 8%
SMPS_1_2_3 L13 SMPS_1_2_3 R181 0,000526 8%
vdd_mpu R181 vdd_mpu U52 0,006311 90%
vdd_mpu R181 vdd_mpu U52 0,006311 92%
vdd_mpu R181 vdd_mpu U52 0,006311 92%
Total Etch Resistance = 0,007007 100%
Total Etch Resistance = 0,006852 100%
Total Etch Resistance = 0,006837 100%
Max Value = 0,007007

Table 8-10 PDN Effective Resistance - From PMIC Source to Device Load

PDN Elements PDN Effective Resistance (Ω) % of Total Etch Resistance
Etch 0,008045 89%
Inductor 0 0%
Sense Resistor 0,001 11%
Max PDN Effectiv Resistance from Source 0,009045 100%

IR Drop: vdd_mpu (PCB RevJan14, Sentinel PSI)

  • Source Conditions: 1.22V @ 5,12A
  • Recommended Reff < 10mΩ
  • Reff = Total Trace Resistance + Sence Resistor = 8,04mΩ + 1mΩ = 9,04mΩ
  • Voltage / IR Drop: 1,22 - 1,179 = 52,6 mV
DRA756 DRA755 DRA754 DRA752 DRA751 DRA750 DRA746 DRA745 DRA744 VAYU_PCB_CPD_5.gifFigure 8-25 vdd_mpu Voltage/IR Drop [All Layers]

Dynamic analysis of this PCB design for the MPU power domain determined the vdd_mpu decoupling capacitor loop inductance and impedance vs frequency analysis shown below. As you can see, the loop inductance values ranged from 1.0 to 1.4nH and were less than maximum 2.0nH recommended.

NOTE

Comparing loop inductances for capacitors at different distances from the processor’s input power balls shows an 18% reduction for caps placed closer. This was derived by averaging the inductances for the 3 caps with distances over 800mils (Avg LL = 1.33nH) vs the 3 caps with distances less than 600mils (Avg LL = 1.096nH).

Table 8-11 Rail - vdd_mpu

Cap Ref Des Model Port # Loop Inductacne [nH] Footprint Types PCB Side Distance to Ball-Field [mils] Value [μF] Size
C356 1 1,4 4vWSE Bottom 897 22 0603
C359 2 1,26 4vWSE Bottom 855 2,2 0402
C360 3 1,33 4vWSE Bottom 850 4,7 0402
C365 4 1,14 4vWSE Bottom 817 0,1 0201
C366 5 1,13 4vWSE Bottom 755 0,1 0201
C367 6 1,07 4vWSE Bottom 758 1 0201
C368 7 1,12 4vWSE Bottom 811 0,1 0201
C369 8 1,06 4vWSE Bottom 690 0,1 0201
C370 9 1,12 4vWSE Bottom 680 0,1 0201
C384 10 1,04 4vWSE Bottom 686 0,1 0201
C385 11 1,07 4vWSE Top 686 0,1 0201
C387 12 1,16 4vWSE Top 755 0,1 0201
C389 13 1,18 4vWSE Top 693 0,1 0201
C391 14 1,14 4vWSE Bottom 693 0,1 0201
C392 15 1,18 4vWSE Bottom 542 0,1 0201
C396 16 1,11 4vWSE Bottom 745 0,1 0201
C91 17 1,1 4vWSE Bottom 515 1 0201
C92 18 1,09 4vWSE Bottom 622 0,22 0201
C93 19 1,01 4vWSE Bottom 504 0,47 0201
C94 20 1,13 4vWSE Bottom 604 0,47 0201
C95 21 1,04 4vWSE Bottom 612 1 0201
C96 22 1,08 4vWSE Top 612 0,22 0201

Loop Inductance range: 1,01 - 1,40 nH

DRA756 DRA755 DRA754 DRA752 DRA751 DRA750 DRA746 DRA745 DRA744 VAYU_PCB_CPD_6.gifFigure 8-26 vdd_mpu Decoupling Cap Loop Inductances

Figure 8-27 shows vdd_mpu Impedance vs Frequency characteristics.

DRA756 DRA755 DRA754 DRA752 DRA751 DRA750 DRA746 DRA745 DRA744 VAYU_PCB_CPD_7.gifFigure 8-27 vdd_mpu Impedance vs Frequency