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LM4040: Difference between LM4040DxI and LM4040DxQ

Part Number: LM4040

Hi Team,

Our customer is asking for some clarification from the datasheet. Would you kindly help?

I just want to confirm, from what I understand from the datasheet, the LM4040xQ is characterized for operation over an ambient temperature range of –40°C to 125°C and should be the same with LM4040xI. Could you explain why is it showing a difference for minimum cathode current at 25 degree C spec? (highlighted below).

In addition, LM4040DxI and LM4040DxQ have the same package SOT23 (DBZ) therefore these devices can replace each other. Correct?

Thank you.

Regards,

Marvin

  • Hello,

    LM4040DxQ is specified over -40 to 125C, while LM4040DxI is -40 to 85C. As such some of specifications are slightly different. The 2 devices are pin-to-pin replacement.

    Hope that helps.

  • Hi Masoud,

    Thank you for your response. However, our customer is looking for elaboration on this, kindly see the questions below:

    On referring section 6.12 and 6.13, I could see that there are changes in three things:
    1. Reverse Breakdown Voltage tolerance
    2. Minimum Cathode Current
    3. Reverse Breakdown Voltage change with Cathode Current Change
    I understand the change in values for both parts LM4040DxQ and LM4040DxI for full range but can you elaborate on how these values are changing at 25 degree C as well.
    Additionally, I wanted to ask Can you please convey that do the specifications for both the parts remain same over -40 to 85 degree C range.
    Are these parts physically same and just approved with testing for a wider range of temperature?

    Regards,

    Marvin

  • Hello Marvin,

    The differences in spec tolerances are due to temperature range used to characterize and test each device. Hope that helps.