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

11.3.1.2 3.3V Digital and Analog Layout - ZCE Four Layer Example

On the AM273 NZN Four Layer Example, the 3.3 V plane is shown routing to and underneath the AM273 device primarily on layer 3. Due to routing limitations caused by a four layer PCB, underneath the AM273 device the 3.3 V plane is split between layer 2 and layer 3.

The 3.3 V planes on layer 2 break up the otherwise solid ground pour on layer 2. The placement of these cutouts was chosen to minimize the impact to the signal return paths for as many GPIO pins as possible. Vias connect the planes on layers 2 and 3 to the BGA ball pads on the top layer and the decoupling capacitors on the bottom layer.

GUID-D09AF2CB-0F8D-44E1-80B4-655F7865E7E2-low.png Figure 11-17 ZCE 4 Layer Example Excerpt – 3.3 V Digital and Analog Power Planes on Layers 2 and 3 and BGA Vias
GUID-9068AA5C-134C-4FE0-9389-6B45C1719B99-low.png Figure 11-18 ZCE 4 Layer Example Excerpt – 3.3 V Decoupling