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Fail with LP2981-33DBVR (LPB3)

Jaime Ramirez38
Prodigy 20 points

We use the LP2981-33DBVR as voltage regulator with an input from 9v until 15v and a voltage output of 3.3v. Many of our products are having problems because the regulator LP2981-33DBVR is not working with an input voltage large than 11v. We detected the regulators that failed has a serigraphy LPB3 (text over the component). We have observed that this (LPB3) is not present in the last datasheet. What is the problem with the LP2981-33DBVR with serigraphy LPB3?

  • 0
    TI__Mastermind 24915 points

    Hello Jaime,

    Welcome to the forums!

    LPB is just the part marking for the device, and I can verify that this is for the correct device, the LP2981-33DBVR.

    One concern I have is thermal overload of the device. If it works up to 11V and then stops working at a voltage higher than that, it may suggest that the power loss in the device is causing it to overheat and shut down.

    The power consumed in the LDO is based on the following equation Vdrop*Iout = Ploss. You can then take the Ploss and multiply it by the package thermal impedance to determine about how hot the device may be getting.

    What is the current consumption of the device? This is a small package and may not be able to handle the full load you are putting through it. If it is because of overheating, we certainly have other devices that can manage higher voltage dropouts with a large output load.

    Best,
    Michael

  • 0 in reply to Michael J Schultis
    Prodigy 20 points

    Hi Michael.

    Thanks for your response.

    The current consumption in our design is 20 mA max.

    I was checking the datasheets of this component and could see that LPB3 is not present in the last specification.

    The next figure is an old specification:

    The next figure is the last specification:

  • 0 in reply to Jaime Ramirez38
    TI__Mastermind 24915 points

    Hello Jaime,

    Can you please try to reattach the images in your previous post?

    Also, can you please share your schematic for how you are using the device?

    Best,
    Michael