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TPS25961: Current limit less than 100mA

Part Number: TPS25961
Other Parts Discussed in Thread: TPS1641, TPS2662

Tool/software:

Dear technical team

I was looking for a small e-fuse switch and the TPS25961 was ideal because its size but I see that it has a lower 

ILIM current of 110mA more or less.

My question here is if I can lower the chip's limit current (around 65-70mA) by tying a resistor from ILIM pin to OUT pin.

Is it possible to do such modification?

Thanks in advance
Ignacio

  • Hi Ignacio,

    No. It is not possible to reduce the current limit further down from 100mA

    Can you share your system specifications and end application to suggest the options.

    BR,

    Rakesh

  • Hello Rakesh

    The system is like the following

    The E-fuse have to be a guard against shortcircuits on the 5V and 12V buses

    The buses have an external connection  and an internal connection that can be selected independently

    The idea here is to limit and protect the regulator output current in the event of a short circuit

    Now, given that the TPS25961 doesn't feature a fault output, only current limiting, I've designed mine using two transistors (5v protection shown here but this is valid for all channels). The fault signal will trigger when the efuse output starts to fall because of current limiting, and will trigger when the output falls below 500mV from the input. 

    that's good, but this will typically trigger at > 100mA (ilim pin open)

    The idea here is to warn the control CPU of a short circuit and that the CPU latches off the efuse as required

    But I'm faced with the possibility of letting this circuit as a fault detection for dead shorts only, if I cannot reduce the current limit of the chip

    cheers

    Ignacio

  • Thanks for the details.

    Please use TPS1641. it can do current limiting down till 30mA and has fault output.

    Best Regards,

    Rakesh

  • Hello Rakesh

    I've read the TPS1641 datasheet, and the problem that I find is that it draws 1.2mA when active, considerably more than the TPS25961.

    What other part can you suggest me for this device?

    best

    Ignacio

  • Hi Ignacio,

    Please see TPS2662