SPRABN2A March   2019  – December 2019 AM3352 , AM3354 , AM3356 , AM3357 , AM3358 , AM3358-EP , AM3359

 

  1.   AM335x Schematic Checklist
    1.     Trademarks
    2. 1 Introduction
    3. 2 Recommendations Specific to AM335x
      1. 2.1  Unused Signals
      2. 2.2  SYSBOOT Configuration and Required Termination
      3. 2.3  System Issues
        1. 2.3.1 Pinmux
        2. 2.3.2 Pullups
        3. 2.3.3 General Debug
        4. 2.3.4 Warm Reset
        5. 2.3.5 Peripheral Clocking
      4. 2.4  Low-Power Considerations
      5. 2.5  Clocking
      6. 2.6  General DDR Guidelines
        1. 2.6.1 DDR2
        2. 2.6.2 DDR3
      7. 2.7  MultiMedia Card/ (MMC)
      8. 2.8  Inter-Integrated Circuit (I2C)
      9. 2.9  LCD
      10. 2.10 Power
      11. 2.11 Touchscreen
        1. 2.11.1 If ADC/Touchscreen is not Used
      12. 2.12 USB
        1. 2.12.1 If USB0 or USB1 is not Used
      13. 2.13 External Interrupt (EXTINTn)
      14. 2.14 Ethernet
    4. 3 References
  2.   Revision History

2.4 Low-Power Considerations

If you are designing for low power, here are some tips to help you optimize your design:

  • The TPS65217C and TPS65217D do not support RTC-only mode. TPS65218 does.
  • On early prototype boards, it is recommended to include small shunt resistors in the voltage rail paths of each of the following rails of AM335x: VDD_MPU, VDD_CORE, VDDS, VDDSHV1-6, VDDS_DDR. This will help you measure the power consumption of each rail and potential pinpoint high power consumption during development. You may also want to add these shunt resistors for other devices power supplies to be able to measure power for key devices. The AM335x EVMs have examples of these shunt resistors.
    • For production, these shunt resistors should be removed from the design (turned into a continuous plane), especially for designs using Smart Reflex.
  • Only GPIO0 signals are capable of wakeup signaling (to wakeup from DeepSleep or RTC modes). Connect wakeup sources only to these GPIOs (GPIO0_0 to GPIO0_31).
  • For your main clock (24 MHz, and so forth) you can use either a crystal or a LVCMOS square wave clock. There is a power benefit to using a crystal because there is hardware inside the chip that can shutoff the crystal entirely during DeepSleep0 (DS0). When using a square wave clock there is unfortunately no mechanism for automatically turning the clock off and on, which results in additional current consumption.
  • If your design uses VTT you should use a pin from GPIO bank 0 to control the regulator. This will enable the regulator to be switched off during DS0.
  • The Cortex-M3 uses I2C0 for communication with the Power Management IC (PMIC) for purposes of reducing the voltage during DS0.