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ISOM8710: ISOM8710 Input side maximum reverse current leakage value.

Ben van den Bergh
Intellectual 526 points

Part Number: ISOM8710

Dear forum members.

From the datasheet SLLSFO4C Table 7.1 the maximum input reverse voltage is 5V.
From the datasheet SLLSFO4C Table 7.9 the maximum input reverse current is 10uA.
We have a implementation where the input to the ISOM8710 will be driven using a constant curren diode and also a series diode (The diode is to protect the CCD from reverse polarity amongs others).


However due to the above spesifications does this imply that the absolute worst case reverse leakage of the series diode must be less than 10uA (Across temperature, voltage and process variations)
To protect the ISOM8710 input circuit?
Alternativley we could also add an aditional very low leakage diode in parallel across  pins 1 and 2 of the ISOM8710's input.
This however will unfortunately add another part to the BOM.
In short did we interprete the datasheet spesification regarding input reverse current correctly?

Thank you

 

  • 0
    TI__Mastermind 34580 points

    Hello Ben, 

    Thank you for reaching out. Before we start, please note that a newer version of the datasheet is available online: SLLSFO4D.

    Input reverse voltage (VR) is an absolute maximum spec and cannot be violated. The VR spec indicates that if the reverse voltage exceeds 5V the ISOM811x may be damaged. 

    The Input reverse current (IR) is an electrical specification and is therefore a performance indicator.  At the given test condition (VR = 5 V, TA = 25 ºC) the IR will not exceed 10uA reverse current. For voltages below VR=5V, no additional current will be pass in the reverse direction (except 10uA). 

    No additional protections would be needed as long as the reverse voltage at pins 1 and 2 does not exceed 5V. 

    Best,
    Andre

  • 0 in reply to Andrew J
    Intellectual 526 points

    Hello Andre,

    Thank you very much for the detailed reply.
    This helped us a lot.

    Regards

    Ben