• State TI Thinks Resolved
  • Locked Locked
  • Replies 7 replies
  • Answers 1 answer
  • Subscribers 85 subscribers
  • Views 734 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.

Reset Circuit, TMS320C28346, Delfino

Ue
Genius 17175 points
Other Parts Discussed in Thread: TMS320C28346, TPS65001, TPS650061

Hi all

What is the recommended reset-circuit for the TMS320C28346 ?

In the control-card schematic I find a TPS3828-33 monitoring the 3.3V, so I assume we recommend to just monitor the 3.3V.

However, min. reset voltage for the TPS3828-33 is 2.86V over temp.

In the TMS320C28346 Datasheet page 101 I find

Recommended Operating Conditions for the 3.3V: min. 3.14V.

This doesn´t really fit.

Best regards

Ueli

  • 0
    TI__Guru** 119520 points

    Ueli,

    The TI power team just updated their recommendation for the 34x series to the latest power converter: TPS65001

    http://focus.ti.com/docs/prod/folders/print/tps65001.html

    TPS650061
    •Up to 90% Efficiency
    •Mode Control PIN
    •Power Safe mode for
    Light Load Efficiency
    •2.25MHz for Small
    Inductors
    •DCDC output adjustable for 1.2V/1.1V
    •Power Good Signal
    •EMI Suppression
    •Individual EN pin
    •3x3mm QFN

  • 0 in reply to ChrisClearman
    TI__Genius 17175 points

    Hi Chris

    Thank you for pointing this out.

    Looking at the Datasheet of the TPS65001 I find +/-10% tolerance for the SVS trip-point.

    With this solution we cannot guarantee the 3.3V to be within the specified window (3.14V min).

    Can this be a problem ?

    Best regards

    Ueli

  • 0 in reply to Ue
    TI__Guru** 119520 points

    Ueli,

    First, it looks like there is some confusion on the part number, you'll notice two different versions in my post above. The 65001 is the current solution on the market, but there is a new solution in PREVIEW status (set to release in November) that is actually the one I think you should look at: 650061

    http://focus.ti.com/docs/prod/folders/print/tps650061.html

    Also, I'm sending this thread to the owner of these TPS devices and I'll have her respond here.

  • 0 in reply to Ue
    Prodigy 20 points

    Hi Ueli:

    Please see figure 28, the reset cirucit of RSTSNS is compared with 0.6V, the resistor divider could be set to accurate detect reset threshold.

    (For ex, to guarentee reset of condition below 3.3V, set Rs1 560 ohm and Rs2  ohm)

    Which line are you seeing 10% tolerance, are you referring to the power good signal?

    Let me know if this clarifies.

    Best regards,

    Jasmine

     

  • 0 in reply to Jasmine Ng
    TI__Prodigy 470 points

    Ueli,

    I'm not aware of a reset supervisor that lets us dial in a specifc voltage. So Jasmine's solution of using a voltage divider would be your best option.

    Regards,

    Matthew

  • 0 in reply to Matthew Webster
    TI__Genius 17175 points

    Hi all

    The 3.3V for the TMS320C28346 have a 5% tolerance.

    With a 10% tolerance supervisor we cannot guarantee to stay in the specified window.

    The resistor-divider will not improve the accuracy but will always degrade it ....

    Best regards

    Ueli

  • 0 in reply to Ue
    Prodigy 20 points

    Hi Ueli:

    We could tighten the spec to 4% regarding to reset voltage trip voltage, with the guarentee from design and the supported ATE data.

    Sincerely,

    Jasmine