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LM25088: GND to RES Pin = Infinite current limit. Details about that?

Part Number: LM25088

Hello,

With the LM25088, there are 2 versions.  The LM25088-1 offers dithering, and the LM25088-2 offers overload restart timing. They use the same pin for these two different purposes. 

For production, we're considering using both IC's interchangeably and not have either feature enabled. This is due to the current unpredictability of the market availabilities. 

Disabling dither for a LM25088-1 is as simple as connecting GND to the DITH pin. 

If that same RES pin is grounded on the LM25088-2, the below performance is in place... 

Page 18 from the datasheet:

"Cycle-by-Cycle only: The hiccup mode can be completely disabled by connecting the RES pin to GND. In this configuration, the cycle-by-cycle protection will limit the output current indefinitely and no hiccup sequence will occur"

Can someone please explain what is meant by "indefinitely" as opposed to a hiccup pattern? If the circuit is overloaded and the RES pin is grounded, it just means that the once the overload is reached the circuit will shut down completely and not make any attempt to restart itself? And in that event, the end user will need to manually power down and power back up again? 

Is there any other performance loss / sacrifice when the RES function pin is grounded?

https://www.ti.com/lit/ds/symlink/lm25088.pdf?ts=1648229356635&ref_url=https%253A%252F%252Fwww.google.com%252F

Thanks!

  • Hello Jim 

    The cycle-by-cycle protection will limit the output current continuously without any hiccup operation if the RES pin is grounded. 

    Basically, those two devices work identically if the DITHER/RES pin is grounded,

    - Eric Lee (Applications Engineering) 

  • Hello
    I am closing this thread since I have not heard from you for sometime.
    If you are still trying to resolve the issue, please feel free to open a new thread or reopen this thread. Thanks
    - Eric Lee (Applications Engineering)