SPRAD61A March   2023  – November 2023 AM2732 , AM2732 , AM2732-Q1 , AM2732-Q1

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 Introduction
    1. 1.1 Acronyms
  5. 2 Power
    1. 2.1 Discrete DC-DC Power Solution
    2. 2.2 Integrated PMIC Power Solution
    3. 2.3 Power Decoupling and Filtering
    4. 2.4 Power Consumption
  6. 3 Clocking
    1. 3.1 Crystal and Oscillator Input Options
    2. 3.2 Output Clock Generation
    3. 3.3 Crystal Selection and Shunt Capacitance
    4. 3.4 Crystal Placement and Routing
  7. 4 Resets
  8. 5 Bootstrapping
    1. 5.1 SOP Signal Implementation
    2. 5.2 QSPI Memory Controller Implementation
    3. 5.3 ROM QSPI Boot Requirements
  9. 6 JTAG Emulators and Trace
  10. 7 Multiplexed Peripherals
  11. 8 Digital Peripherals
    1. 8.1 General Digital Peripheral Routing Guidelines
  12. 9 Layer Stackup
    1. 9.1 TMDS273GPEVM Layer Stackup
      1. 9.1.1 TMDS273GPEVM Key Stackup Features
    2. 9.2 Four Layer ZCE Example Layer Stackup
      1. 9.2.1 ZCE Four Layer Example Key Stackup Features
    3. 9.3 Four Layer NZN Example Layer Stackup
      1. 9.3.1 NZN Four Layer Example Key Stackup Features
  13. 10Vias
  14. 11BGA Power Fan-Out and Decoupling Placement
    1. 11.1 Ground Return
      1. 11.1.1 Ground Return - TMDS273GPEVM
      2. 11.1.2 Ground Return - ZCE Four Layer Example
      3. 11.1.3 Ground Return - NZN Four Layer Example
    2. 11.2 1.2 V Core Digital Power
      1. 11.2.1 1.2 V Core Digital Power Key Layout Considerations
        1. 11.2.1.1 1.2V Core Layout - TMDS273GPEVM
        2. 11.2.1.2 1.2V Core Layout - ZCE Four Layer Example
        3. 11.2.1.3 1.2V Core Layout - NZN Four Layer Example
    3. 11.3 3.3 V Digital and Analog Power
      1. 11.3.1 3.3 V Digital and Analog Power Key Layout Considerations
        1. 11.3.1.1 3.3V Digital and Analog Layout - TMDS273GPEVM
        2. 11.3.1.2 3.3V Digital and Analog Layout - ZCE Four Layer Example
        3. 11.3.1.3 3.3V Digital and Analog Layout - NZN Four Layer Example
    4. 11.4 1.8 V Digital and Analog Power
      1. 11.4.1 1.8 V Digital and Analog Power Key Layout Considerations
        1. 11.4.1.1 1.8V Digital and Analog Layout - TMDS273GPEVM
        2. 11.4.1.2 1.8V Digital and Analog Layout - ZCE Four Layer Example
        3. 11.4.1.3 1.8V Digital and Analog Layout - NZN Four Layer Example
  15. 12References
  16. 13Revision History

11.1 Ground Return

All available ground return BGA balls should be utilized to create the best possible electrical and thermal connection between the AM273x package and the attached PCB. Roughly the center 7 x 7 BGA balls on the ZCE package and 5x6 BGA balls on the NZN package are dedicated to ground return with a few other I/O return paths placed near the edges of the BGA. For best thermal performance, solid ground return planes should be used directly under the BGA on as many layers as possible.

The AM273x contains both analog and digital ground return pins. Both analog and digital ground return pins should be shorted to a common set of ground return planes on the PCB for best noise and EMI performance as this creates the lowest possible impedance path for all return currents to follow. It is not recommended to separate these two return paths as this typically ends up with lower performance return paths for both digital and analog signal paths.