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CSD15380F3: Maximum drain-to-source leakage on datasheet

Part Number: CSD15380F3

Hi there,

I'm working on an application which requires a very low leakage small signal N-channel MOSFET. As far as I can tell, the CSD15380F3 has the lowest max Idss listed of any TI MOSFET (please correct me if I'm wrong).

I'd like some clarity on how firm a guarantee the 50nA figure is. How was it obtained - by testing, or by design? If by testing, is it a three-sigma value or something else?

Finally, the 50nA figure is guaranteed at 25 degrees C. Is there any data for slightly elevated temperatures? I need the low-leakage for long-term device storage, and ideally the device will be stored at room temperature, but there's always a risk it ends up in a non-air conditioned warehouse in Phoenix in the summer.

Thanks!

  • You are correct 50nA is the lowest rated Idss leakage value we have. The reason for that is this is as low as we can test in production - all of our parts are screened for IDSS leakage at room temperature and test to this limit.

    We would test lower if we could, but since we do not have that capability, there is a fair bit of margin between the typical value for IDSS and the limit specified on the datasheet (>>3 sigma) but we cannot guarantee anything beyond the datasheet value.

    As mentioned, the test is conducted at room temperature (Ta = 25deg) and we would expect this parameter to increase with temperature.

    So for 75 degC, we saw measure increase of ~6% over the 25 deg data. But this curve is exponential, so for 125deg data, the 25deg leakage increased by a factor of 2.5x.

    Hopefully this helps answer your question. All that said, I think in a warm warehouse, you won't see to much deviation from the typical values.

    As a final word, I see this is for a medical application. I would just caution that at this time, there are no plans to qualify the CSD15380F3 for use beyond standard commercial applications.
  • Thanks Brett, that satisfies my questions. This part should work fine for my application. I always prefer to check when a limit is important, since I was burned once before by a product from another semiconductor manufacturer (they had a datasheet-declared minimum value which I was depending on, but it was only guaranteed "by design" and wasn't tested on actual fabbed silicon - real-world performance turned out to be much worse than limits specified on the datasheet).

    Understood on the commercial ratings - the usual at-own-peril applies.

    Thanks again!