• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 62 subscribers
  • Views 614 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.

TPS65070 Support for TMS320C6748 DVFS?

Scott Burton
Prodigy 230 points
Other Parts Discussed in Thread: TPS65070, TMS320C6748

Hello Forum,

My design will be using a TPS65070 to power a TMS320C6748 DSP. This DSP supports Dynamic Voltage and Frequency Scaling (DVFS) on its core logic (CVDD) rail. With DVFS the DSP commands via I2C that this rail be changed as required between 1.0/1.1/1.2/1.3V operating points to optimize performance and minimize power consumption.

1/ The first page of the TPS65070 datasheet highlights that it supports Dynamic Voltage Scaling on LDO2 but doesn't make the same declaration for the three DCDC converters. Could you confirm that the the output voltages of DCDC1, DCDC2 and DCDC3 can also be changed dynamically via I2C as per the page 58/59 output voltage bit mapping?

2/ The column heading of the slew rate table at the bottom of page 59 states "VDCDC3 Slew Rate", but the text above indicates that the table applies to DCDC2 as well. Is this correct? Does the same table also apply to DCDC1and LDO2?

4/ The table at the top of page 61 shows the output voltage bit mapping for LDO1, but there's no mention of what slew rate would apply to this output. Can LDO1 be changed dynamically?

5/ Page 94 of the TMS320C6748 DSP datasheet states that "TI provides software components (called the Power Manager) to perform DVFS and abstract the task from the user." Could you tell me if this software, running on the TMS320C6748, will allow it to dynamically control the TPS65070 output voltages?

Thanks very much in advance for your help!

Regards,

Scott

 

 

  • 0
    TI__Prodigy 730 points

    Hi Scott,

     

    1) Yes DCDC1-3 voltage can be changed with I2C writes to the registers. 

     

    2) The slew rate applies to DC2 and DC3 but not DC1. It will also apply for LDO2 if the LDO Tracking Bit is set to 1 (i.e LDO2 voltage follows DCDC3 level). If the tracking bit is not set, the LDO will ignore the slew rate setting.

     

    4) LDO1 can be set dynamically via I2C just as the other regulators on the chip. There is no slew control for this regulator.

     

    5) I am not sure about the software. Perhaps another member would know. 

     

    Hope this helps. 

     

    Kind Regards,

    Matt Roberts 

  • 0 in reply to Matt Roberts
    Prodigy 230 points

    Hi Matt,

    Thanks very much, it certainly does help.

    I'll check with the DSP Forum on the software.

    Thanks again,

    Scott