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TPS6521855: DDR4 application

Hirotsugu Kobayashi
Mastermind 8485 points
Part Number: TPS6521855
Other Parts Discussed in Thread: TPS6521815, TPS65218, BOOSTXL-TPS65218

Hi team,

I would like to change DCDC1 of TPS6521855 to 1.2V and use it for DDR4 application.

Should I change only the DCDC1 register of the TPS6521855?

Or should I write all the setting values to the blank TPS6521815?

They are used in mass production.

Best Regards,

  • 0
    TI__Genius 15725 points

    Hello,

    Thank You for using E2E! We recommend using the user-programmable version (TPS6521815) if any of the settings on TPS6521855 (or any other pre-programmed PN) do not meet the system power requirements. We have the programming board (BOOSTXL-TPS65218) available in the product folder on ti.com that can be used to re-program the PMIC with custom settings for prototype. For production volumes of a custom NVM, there is an option to work with a TI approved distributor (i.e. Arrow). 

    Just for reference, we have a new PMIC that is currently under prototype phase (expected to be released around march-2023 time frame) and that can also be used to power the AM64 processor + DDR4 applications. Here is the link to the product folder where we have technical documentation available showing how this PMIC can power the AM62 processor which has similar voltage/sequence requirements as the AM64. Link: TPS65219 product folder

    Thanks,

    Brenda

  • 0 in reply to Brenda Diaz
    Mastermind 8485 points

    Hi Brenda-san,

    I think it would be the same using either IC, but what is the reason for recommending the TPS6521815?

    I have only a few TPS6521855.

    Is it possible to overwrite TPS6521855?

    Best Regards,

  • 0 in reply to Hirotsugu Kobayashi
    TI__Genius 15725 points

    Hi,

    TPS6521815 is the user-programmable version which comes with all the rails disconnected from the sequencer (rails are disabled in Active state). This allows customers to make changes to the register settings and save those values into the EEPROM before the PMIC executes the power-up sequence. 

    Since I2C communication is not available in OFF state, any pre-programmed variant (i.e. TPS6521855) will trigger the power-up sequence and turn-ON the rails before customers are able to change output voltages or any other setting in the PMIC. This is because I2C communication is only available in Active state. If you only have a few TPS6521855 samples and the programming board (BOOSTXL-TPS65218) and they will be used for prototype only, then you can re-program the Buck1 output voltage before the PMIC is soldered into the prototype. This should be ok for evaluation only. Let me know if yo have any questions about the programming steps. 

     

    Thanks,

    Brenda

  • 0 in reply to Brenda Diaz
    Mastermind 8485 points

    Hi Brenda-san,

    Thanks for the explanation, I understood as below.

    In the case of TPS6521815, it becomes Active state without any output and can be rewritten via I2C bus.

    In the case of the TPS6521855, it becomes Active after all outputs and can be rewritten via the I2C bus.


    What is the reason why rewriting TPS6521855 with (BOOSTXL-TPS65218) cannot be used in mass production?

    What are the risks of outputting once when rewriting?

    Best Regards,

  • 0 in reply to Hirotsugu Kobayashi
    TI__Genius 15725 points

    Hi, 

    That's correct, TPS6521855 will have the rails enabled in Active state and TPS6521815 has all the rails disabled by default in Active state.

    Re-programming a non user-programmable (i.e TPS6521855) is not recommended and one of the reasons is because for customer returns and technical support we identify the EEPROM settings based on the part number and top marking. It is technically doable but just not recommended.   

    Thanks,

    Brenda

  • 0 in reply to Brenda Diaz
    Mastermind 8485 points

    Hi Brenda-san,

    I understand, the part will be changed to TPS6521815.
    Do you have any plans to release TPS65218xx products that support DDR4?

    Best Regards,

  • +1 in reply to Hirotsugu Kobayashi
    TI__Genius 15725 points

    Hi,

    Since our new PMIC (TPS65219xx) can power the AM64 processor + DDR4, we do not plan to release another orderable for TPS65218 to power the same application and use case. 

    Thanks,

    Brenda