• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 62 subscribers
  • Views 429 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

WEBENCH® Tools/TPS82130: Inrush Current and Soft Start

Caitlin Slayden
Prodigy 80 points
Part Number: TPS82130

Tool/software: WEBENCH® Design Tools

Hello,

I am wondering how the TPS82130 operates when a system initially powers up, and there are many circuits which begin to turn on as the output of the TPS82130 is high enough to enable everything else downstream.  Lets assume the TPS82130 supplies some "5V Rail" voltage in a system, and there are many other circuits reliant on this Rail voltage.  Each other circuit has a low steady state draw, but has some decent inrush current on startup.  if the TPS82130 is not fully on yet, but is outputting >2.5V, which is enough to get other components started, then how does the TPS82130 act in this scenario?  

Having a longer (~10ms) soft start on the TPS82130 is preferable, because there is some inrush current on the input as well.  Am I forced to limit the current on the circuits downstream or stagger when these circuits power up?

Is there a risk of this chip being damaged in the high-load-demand-before-it-is-fully-on situation? 

all I see in the datasheet is section 7.3.3, which still left me wanting some explanation in this scenario.

Thank you 

  • 0
    TI__Guru*** 142860 points
    Hi Caitlin,

    No, there is not really a chance to damage the TPS82130 from this, as it has current limit. If the output current gets high enough, current limit will be reached and Vout will drop as the IC limits the output current.

    However, there are concerns for your system. The large inrush at the output creates a corresponding inrush at the input which might interfere with your input source.

    I recommend tuning the SS time, using the PG output to hold off the loads, and/or sequencing the loads to minimize any inrush currents in your system. This is a good design practice in general.