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TPS659037: Modifying power up sequence

Michael Balourdas
Expert 5455 points
Part Number: TPS659037

Hello,

My customer is evaluating TPS659037 and has some clarifying questions about the power up sequence. What they want to do is use SMPS45 in dual phase mode just as the eval board does to supply VDD_GPU but use SMPS9 as a 3.3V output.  The SMPS9 would supply voltages for VDDShVx supplies at 3.3V and the EMMC.  The SMPS7 supply would supply 3.3V as well, but for other devices on the board.  What’s not clear from the datasheet and user guide is how custom power sequences are programmed into the device.  There are OTP settings that configure default options and the documentation references using GPIO’s to enable external resources.  So the questions are:

  1. What OTP power up sequence settings can be ordered?
  2. Can power sequences be customized to, for example, insert SMPS9 between LDO3_OUT/LDO4_OUT or would they only be able to use the REGEN1 function to enable an external 3.3V supply?  From reading, it doesn’t sound like that’s the case but I’d like to be certain because SMPS7 and 9 aren’t usable for the CPU if that’s the case.

 Thanks,

Michael

  • 0
    TI__Expert 8730 points

    Hi Michael,

    I have forwarded your request to our applications expert and we will get back to you as soon as possible. Please expect 1-2 days delay as she was out of office last week and just returning to office..

    Regards,

    Murthy

  • 0
    TI__Genius 10000 points

    Michael,

    Once these devices are programmed at the TI factory, the default settings cannot be changed. TPS659037 uses OTP (one-time programmable) memory, which specifies the default voltages for all the power rails, the GPIO default configurations, the power sequencing, etc.

    if the customer wants to modify the settings, they can only change the settings after the device has been powered up (through I2C). This means that you could enable/disable rails or change voltages, etc. However, you will not be able to change the power sequence timing or default voltages.

    The available settings we have for this device are located in our user guide: http://www.ti.com/lit/pdf/sliu011

    Thanks,

    Nastasha