• State
  • Locked Locked
  • Replies 1 reply
  • Subscribers 62 subscribers
  • Views 129 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.

TPS25983: Current Limit And Retry

Niv Shalom
Prodigy 30 points
Part Number: TPS25983


Tool/software:

Hi ,

I'm using in my design the TPS25983 in the following schematic:


while making sure the NRETRY is shorted to GND and RETRY_DLY is floating .

ILIM is set to 5A.

when testing current limit function using E- Load,  I'm connecting the load (to V_SYS)  and increasing the load current till it cutoff.
After the cutoff event (FLT is '0'),I'm trying to return to normal operation by decreasing the current under the current limit value but only when the current reach  ~0.5A the operation return to normal (FLT is returning to '1').

I've tested with CC mode loader and CR mode loader , on CC mode the E-fuse returned to normal on ~0.5A and on CR mode the E-fuse returned to normal on ~1.5A.
what can cause this problem?
Is there a way to immediately return to normal operation when the load drops below the ILIM?

Thank you,
Niv

  • 0
    TI__Mastermind 39295 points

    Hi Niv,

    We don't recommend testing current limit using CC mode since both the eload and the device will behave like a current source connected in series which can result in unexpected shutdown.

    CR mode is fine for testing.

    Now your question of returning back after the OCP. If you have reduced the load, during the device auto-retries, the device should be able to perform the startup.

    I suspect that the device is failing the startup due to high resistive load when performing the startup.

    In your schematic, I see dvdt cap is 100nF which is very large resulting in slow startup and more power dissipation due to high continuous current draw due to resistive load.

    Can you change the dvdt cap to 1nF and try again to see if this resolves your issue.

    Also can you tell me how much Cout do you have?

    Best Regards,
    Arush