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TPS65219: I2C connection between PMIC and AM64

Oba
Genius 17335 points
Part Number: TPS65219

Hello,

I'm not sure which forum I shoud post, but my customer has some question for TPS6521904 and AM64x connection.

Hello,

 

My customer is designing their prototype with AM64x with TPS6521904.
Then they have several questions.
 

1.
According to SLVAFE9 application note, I2C0_SCL/SDA of AM64x are connected to SCL/SDA of TPS6521904.
The application note says that the I2C (or VSEL_SD pin) is used for changing LDO1 for SD card voltage.
Also SPRACU5 application note says, the I2C0 have to connected to PMIC if using TI provided S/W.
Is I2C port used for only LDO1 voltage? 

My customer wants to use the I2C0 pins for other purpose.
Then they wonder if this I2C0_SCL/SDA have to be connected to PMIC if they don't need change from the default setting.
Is the connection absolutely required?

2.

In addition to I2C0 ports, 2GPIO ports are connected to VSEL/VSEL_DDR and MODE/STBY.
Are these 2 GPIOs also absolutely required?

Regards,
Oba

  • +1
    TI__Mastermind 22421 points

    Hi Oba,

    Thanks for reaching out. Please find my feedback below and let us know if you have any questions.

    • The TPS6521904 NVM is configured to control the output voltage of LDO1 with the VSEL_SD pin. Here is the polarity:
      • VSEL_SD pin HIGH, LDO1=3.3V (requires supplying PVIN_LDO1 with 3.3V)
      • VSEL_SD pin LOW, LDO1=1.8V

    • Customer will need I2C communication to read the interrupt registers, to clear the "W1C" register fields after a PMIC fault is resolved, to trigger a COLD reset (if needed) and to trigger an OFF request by software. I recommend submitting a E2E to the processor forum to get more information on the AM64 software/SDK and key scenarios where I2C communication might be needed.

    • The TPS6521904 NVM has the MODE/STBY pin configured to select the switching mode between auto-PFM (pin state = low) and forced-PWM (pin state = high). Customer can have an external pull-up or pull-down to select the switching node without connecting this pin to the processor.

    • The connection of the VSEL_SD pin will depend on how they plan to use LDO1. If customer does not need to switch the voltage on this rail during operation, they can just have an external pull-up or pull-down without connecting the pin to the AM64 processor. The state of the VSEL_SD pin needs to be set before LDO1 turns-ON. 

    Thanks,

    Brenda