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TPS62810-Q1: Load transient response

user6142633
Intellectual 470 points
Part Number: TPS62810-Q1

Hi,

I use TPS62180-Q1 as below figure 4.

To set Vout = 0.61V, I chose the value of R1&R2 is 1k&47kΩ.

In this condition, evaluating load transient, I got the result as below.

When load current is increasing, the drop of output voltage is small.

However, the overshoot is big after the drop.

When the value of Cff is changed (open, 10pF, 22pF, 100pF), the result is almost same.

Let me know how to reduce the overshoot.

Regards,

  • 0
    TI__Genius 17421 points

    Hi,

    Could you provide more information regarding the test conditions which was used for the TPS62810-q1 load transient measurements and could you upload the images again? I am not able to open it.

    Best regards,

    Tanvee

  • 0
    TI__Intellectual 1525 points

    Hi,

    It looks like your screenshots are missing here and without them, it is difficult to understand the nature of the problem.

    Also, the layout you're using would be helpful to find any issues caused by parasitics. If it is confidential, you can reach out to me via e-mail.

  • 0 in reply to Bjoern Goerner
    Intellectual 470 points

    (I mistook uploading figure in previous post. Repost)

    Hi,

    I use TPS62180-Q1 as below figure 4.

    To set Vout = 0.61V, I chose the value of R1&R2 is 1k&47kΩ.

    In this condition, evaluating load transient, I got the result as below.

    When load current is increasing(0 → 1.2A), the drop of output voltage is small.

    However, the overshoot is big after the drop.

    Changing the value of Cff  (open, 10pF, 22pF, 100pF), the result is almost same.

    In Both PWM and PFM mode, the overshoot occured.

    Let me know how to reduce the overshoot.

    Regards,

  • 0 in reply to user6142633
    TI__Genius 17421 points

    Hi,

    Increasing the output capacitance will make an impact on a transient response but there are other factors like slew rate, measurement techniques will affect the transient performance as well. Schematic looks ok here and would suggest checking measurement setup. 

    App note provides more detail about measurement setup: http://www.ti.com/lit/an/snoa895/snoa895.pdf 

    In addition, you can check the device performance on WEBENCH for the condition.

    Best regards,

    Tanvee