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TPS54340-Q1: Device function at over current

Part Number: TPS54340-Q1

Hi Team,

One of my customer using this device have below query during over current operation. Please help with output voltage to output current graph (Or Input v Output current)

If the load draws 3.5A< Iout < 6.8A, will the Regulator go to frequency fold back mode due to the current limit or go to thermal shutdown?

 Is the max current defined for max output voltage?

Also datasheet mentions open loop current limit is 6.8A max. What is the closed loop current limit?

Please help with your comments and inputs. Thanks in advance for the help and support.

Regards, Shinu Mathew. 

  • Hello Shinu Mathew,

    Answering your questions:

    Please help with output voltage to output current graph (Or Input v Output current) - Sorry to say, but we don't have any such graph to provide you. But I would recommend referring equation 8 on page 16 to understand the maximum switching frequency at which the inductor current remains under control when VOUT is forced to VOUT(SC)

    If the load draws 3.5A< Iout < 6.8A, will the Regulator go to frequency foldback mode due to the current limit or go to thermal shutdown? - The regulator will go into a frequency foldback scenario.

    Is the max current defined for max output voltage? - No

    Also, datasheet mentions open-loop current limit is 6.8A max. What is the closed-loop current limit? - There is a 60ns delay for the loop to react to the open-loop current limit. That is why only open-loop current limit is mentioned in the EC table fo the datasheet. The cLose loop limit just will be maximum inductor current observed in 60ns after the open-loop current limit. For comprehensive understanding, I would recommend reading 7.3.10 section in the datasheet. Hope this helps!

    Please let me know if you have more questions, or please close the thread if you think my response answered your question. Thanks!

    Best Regards,

    Ankit Gupta

    Application Engineer