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TPS2400: Query Related to the Overvoltage Protection IC

Navendu Shekhar
Intellectual 560 points
Part Number: TPS2400
Other Parts Discussed in Thread: TPS2595

Hi TI Team,

We are designing a tracker device which is intended to be placed in Hazardous Zone 0 location. We are following the IEC60079-11 standards to make the device Zone 0 compatible.

The device will  be intrinsically safe and we are using Fuse and Zener diode combination to limit the power in case of fault condition.

It is difficult to find the zener diode with Vz~6V and the max input voltage and current 12V and 1.5A respectively. And by placing the current limiter in series with the znener there will be some volatge drop also.

So we cant use the zener diode part in our schematic to limit the voltage in case of fault condition. Does TI has any solution in that case if we want to protect our device in case of overvoltage? Is the IC which we have selected will be suitable for our use?

It would be better if there is a feature in the IC like fail to open instead of fail to short.

Let me know if you need any more details in this regard

Thanks,

Navendu

  • 0
    TI__Guru* 96041 points
    Hi Navendu,

    TPS259531DSG provides fast overvoltage protection with current limiting feature and could replace Fuse and Zener diode combination in your application. Please have a look and let me know your views.

    Best Regards,
    Rakesh
  • 0 in reply to Rakesh
    Intellectual 560 points
    Hi Rakesh,

    Fuse seems to be much more reliable in comparison to IC in case of short since fuse will open and will stop the current flowing through the circuit but in case of IC we can't say that it will be open or not if fault case is applied. Is the part suggested by you is short circuited in case of fault condition or it will open ?
    It would be better if we get the part which only deals with Overvolatge protection.
    What does this line means"Safe During Single Point Failure Test"?

    Thanks,
    Navendu
  • 0 in reply to Navendu Shekhar
    TI__Guru* 96041 points

    Hi Navendu,

    For the output short circuit condition, the device limits the current to the programmed value set at the ILM pin. The line "Safe During Single Point Failure Test" means even if the reference pin (ILM pin) is OPEN or SHORT by mistake, the device limits the output current to 3A (typ) as mentioned in the 7.5 Electrical Characteristics table.

    Please refer blog e2e.ti.com/.../get-out-of-the-dark-upgrade-your-fuse which highlights the difference w.r.t Fuse. One thing to note is Fuse fails in OPEN where as the semiconductor FETs fail in SHORT but we will never face such scenario as long as the device is operated under ABS MAX voltage.

    Best Regards,
    Rakesh

  • 0 in reply to Rakesh
    Intellectual 560 points

    Images for ref.zipHi Rakesh,

    Thanks for helping. We can consider this part(TPS2595) in our project.

    We have one more query related to this part-

    For ex ia level of protection we need to use 3 independent active voltage limitation semiconductor circuit(attached the image for ref).

    So with this architecture(attached) will it create any issue from design side(if fault in applied on any one TPS  IC)?

  • 0 in reply to Navendu Shekhar
    Intellectual 560 points

    Hi Rakesh,

    I am waiting for your reply on this query.

    I have also attached the Schematic with Fuse part so that you can review it from your side.

    The fuse part which we are using is "TPS259531DSGT".

    We are planning to use it in self controlled feature.

    It would be better if we get your quick response on this query so that we can freeze our design.

    Thanks,

    Navendu

    SCH_501-1-00797_a0_40.pdf

  • 0 in reply to Navendu Shekhar
    TI__Guru* 96041 points
    Hi Navendu,

    Can you please confirm the need for 3 eFuses in parallel for such load current level. Lets discuss on call to close this ASAP.

    Best Regards,
    Rakesh