• State Resolved
  • Locked Locked
  • Replies 6 replies
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 374 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.

TLV62568A: Load transient performance

chentsu chung
Mastermind 6180 points
Part Number: TLV62568A

Hi Team,

1. From datasheet Figure23., the Vp-p is about 0.2V, But it is 0.1V(+-2.5%) when I using Webench simulation.

What makes the difference? Which one I can refer to?

2. Now my application is 0A to 200mA, Vout is 1.2V within +/-5%, does TLV62568A could meet the spec?

Thank you,

C.T.

  • 0
    TI__Mastermind 37481 points
    Hi Chentsu,

    Please see below response.

    1. From datasheet Figure23., the Vp-p is about 0.2V, But it is 0.1V(+-2.5%) when I using Webench simulation.

    What makes the difference? Which one I can refer to? --> Please attached the schematic diagram and BOM for the Webench simulation so I can make the comparison.

    2. Now my application is 0A to 200mA, Vout is 1.2V within +/-5%, does TLV62568A could meet the spec? --> I strongly believe that TLV62568A will be able to meet the specs. Just put an options for feed forward capacitor (Cff) and total output cap of 47uF for transient response optimization.


    Best regards,
    Excel
  • 0 in reply to Excel Regidor
    Mastermind 6180 points
    Hi Excel,

    About the question, I use 5Vin, 1.8V/1A output for load transient.

    I know the design in datasheet is 2A output, but Webench can only do load transient for 0% to 100%, so I have maked sure that the inductor is the same(1.0uH).

    Or, could you help to simulate a similar load transient result(like Figure23 in datasheet) and let me know your setting?

    Thank you very much.
    C.T.
  • 0 in reply to chentsu chung
    TI__Mastermind 37481 points

    Hi C.T.,

    Transient load can be adjusted to the desired level in Webench although the min. current is 50mA. But step-load response has minimal change between 0A to 50mA (min load) because the device is always at PWM mode. Based on the simulation result, it has 20mVp-p output deviation. See below schematic diagram and transient load simulation result for your reference.

    Note: I suggest to add a capacitor option across Rfbt in the schematic diagram in case there is a need to optimize the step-load response in the future.

    Best regards,

    Excel

  • 0 in reply to Excel Regidor
    Mastermind 6180 points
    Hi Excel,

    Thank you, but I can get this result from Webench. My question is, I can't get any result like Figure23.
    Why the result from Webench is always lower than Figure23 very much. I don't know which one I should belive.

    So that is why I ask for the difference between Webench and Datasheet. Or the result difference is only at the 50mA min. load?

    Thank you,
    C.T.
  • 0 in reply to chentsu chung
    TI__Mastermind 37481 points

    Hi C.T.,

    To have some short of align of the datasheet result vs. Webench, you need to adjust the rise and fall time of the pulse current source to 1us. This is to have the same current slew rate with the datasheet. However, because the whole circuit is simplified model to have fast simulation, it cannot 100% replicate the exact behavior of the system.

    Please see below pulse current source setting and transient load response (5.0Vin, 1.8Vout).

    amCharts.pdf

    Best regards,

    Excel

  • 0 in reply to Excel Regidor
    Mastermind 6180 points
    Hi Excel,

    Understand, thanks for your help, I found where I can modify the load parameter.
    Thank you very much!

    C.T.