LT3081 Overload Recovery - Applies to Many LT308X LDOs

Here is a question that I received from a customer quite a while ago, but I will post the question here and then also post the answer since the question applies to multiple LDOs and I get similar questions frequently.  Here is the customer's question:

"I am using an LT3081 in an application and I have noticed that in an overcurrent situation the regulator seems to latch out and does not self-recover. I am using the DC1870A evaluation board. Is that normal operation for this regulator? I would expect it to limit the current at the maximum until the overcurrent situation goes away and then automatically go back to voltage regulation."

  • +1
    •  Analog Employees 
    on Jan 9, 2020 5:28 PM 9 months ago

    This is how I answer the question posted above:

    There is a text section in the LT3085 datasheet called Overload Recovery that is probably applicable to your scenario with the LT3081.  The image below shows the text section from the LT3085 datasheet:

     

     LT3085 DS text excerpt_1.png

    The image below shows the Current Limit curve from the LT3085 datasheet that is referenced in the text excerpt above. Your LT3081 has a similar Internal Current Limit curve in the datasheet:

    LT3085 DS  CL curve_1.png

    Check your specific datasheet for a Note similar to Note 9 from the LT3085 datasheet that I show in the image below that addresses current limit:

    LT3085 DS Note 9_1.png