• State TI Thinks Resolved
  • Locked Locked
  • Replies 5 replies
  • Answers 3 answers
  • Subscribers 64 subscribers
  • Views 297 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LP8758-E0: supports dual-phase interleave?

Jerry Chen
Expert 5110 points
Part Number: LP8758-E0

Hi,

I saw a customer use this device in dual-phase interleave configuration to support larger than 4A. Does it support this setting? How?

Thanks.

  • 0
    TI__Mastermind 49261 points
    Hi Jerry,
    LP8758-E0 is released catalog OTP configured as single phase 4 individual buck converters; although its I2C access allows to change many parameters, but phase configuration is not allowed to be changed by I2C.
    Customer may use it in "dual-phase" by changing its 2 rails' voltage into same level and connecting them together; this requests the system having a I2C master and powered on first.
    BTW, if 4A in the peak load current and load profile is not too heavy to cause overheat, the device has 2 rails to support up to 4.5A.
    Please let me know if you have more questions.
  • 0 in reply to Phil Yi
    Prodigy 80 points
    Hi Phil, hi Jerry

    Phil tells about "Customer may use it in dual-phase". In the datasheet there is currently no information about dual phase configuration, but the GUI application for the evaluation board LP8758E0-EVM has a switch "Force Multi-phase PWM" for Buck0 and Buck2. Comparing the register dumps it shows that this switch corresponds to BUCK0_CTRL1[0] and BUCK2_CTRL1[0]. Both bits are declared as reserved in the datsheet.

    It looks like as Buck0/Buck1 are a Master/Slave group and Buck2/Buck3 are a Master/slave group, too.

    If setting BUCK0_CTRL1[0] and BUCK0_CTRL1[1] both to '1' = "Force Multi-phase PWM" + "Force PWM"
    is there a possibility to drive them to the same voltage and connecting them together to get 8A ?
    The schematic would be similar to -B0 revision, but with just two channels per group instead of four.

    Thanks!
    Ingmar
  • 0 in reply to user3930661
    TI__Mastermind 49261 points
    Hi, Ingmar,
    The GUI switch "Force Multi-phase PWM" works for -B0 OTP and other Multi-phase devices only; for -Ex OTP devices, it doesn't do phase re-configuration.
    By setting rails into exact same voltage level, it's possible to connect same voltage rails together to get higher load current; but it's not recommended since special care must be done for sharing the load evenly between rails and also the voltage setting must be done before turn them on.
  • 0 in reply to Phil Yi
    Prodigy 80 points
    Hi Phil,

    thank you for the answer. You are right, load balancing could be an issue.

    By the way.. off topic...

    As many customers asked already for in system OTP programming:
    Why TI doesn't sell blank OTP parts, which should boot up with all outputs disabled.
    A programming utility (cmd-line or GUI) for custom programming based on the setup found with the EVM board GUI would be fine.
    The utility could even program any needed 'hidden' OTP values as well.
    This would make this part perfect for many use cases, where a power management controller is not available.

    Thanks Ingmar
  • 0 in reply to user3930661
    TI__Mastermind 49261 points
    Hi, Ingmar,
    Thanks a lot for the suggestion! Actually, we're planning to make effort to implement it but not fully done yet; we'll continue and hope to have it released to public soon.