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TPS25981: TPS25981 Steady state current limiting

Sahin Bozkurt
Prodigy 80 points
Part Number: TPS25981
Other Parts Discussed in Thread: TPS25980, TPS25982

Tool/software:

I have a question. I would like to use this IC in a 12V output voltage line with a 7.5A current limit. Would this IC be a suitable choice? Even if the load tries to draw 8A, it should limit the current to 7.5A and provide this limited current for about a couple of 100ms. I would be very grateful if you could help. Thank you in advance!

  • 0
    TI__Mastermind 39045 points

    Hi Sahin,

    Overcurrent response for this IC is circuit breaker so when the load current is 8A, this device will break the circuit. This device also have blanking timer so you can set for how long you want to allow higher current before overcurrent protection breaks the circuit.

    This eFuse can handle the mentioned operating conditions but you need current limiter eFuse if you want to limit the current. Consider TPS25980/2/3 device family based on current requirement. 

    Best Regards,
    Arush 

  • 0 in reply to Arush Gupta
    Prodigy 80 points

    Thank you for your response. I have a few more questions I'd like to ask. I want to use the TPS25980 IC you recommended in front of a circuit that draws a high inrush current when powered on, limiting it to 7.5A with a required duration of around 100ms. Can I use this IC to provide a steady 7.5A for 100ms? For example, if I use this IC and select the appropriate surrounding components, even if the connected 10V output line tries to draw 8A, it will limit the output to a steady 7.5A for 100ms, providing a consistent output of 10V * 7.5A = 75W. During this period, the current and voltage will remain stable without any drop, supplying the desired power to the circuit. I reviewed the datasheet, but I couldn't find a section that specifically addresses this point. If possible, could you point me to the relevant page so I can examine it in detail?

  • +1 in reply to Sahin Bozkurt
    TI__Mastermind 39045 points

    Hi Sahin,

    During the current limit mode, the device only regulates the current. Vout is not equal to Vin. It will be Vout = ILIM * Rload. The vout will remain stable but at this level. When the device limits the current, there will be slightly higher power dissipation on the device. This may cause Thermal shutdown and time to TSD will depend on power dissipation on device (PD = (Vin-Vout)*ILIM) fig 25 in TPS25982 datasheet

    It seems, I have made an error while recommending. TPS25980 do not have current limiting variant hence you weren't able to find any details about this. Kindly refer to TPS25982X device with 'L' variants having current limiting response. (Section 8.3.3.3)

    Best Regards,
    Arush 

  • 0 in reply to Arush Gupta
    Prodigy 80 points

    Thank you for your support and quick response.