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LM5101C: The pulse width becomes narrower

Guru 11170 points
Part Number: LM5101C
Other Parts Discussed in Thread: LM5101

Hello E2E,

Our customer is using the LM5101CMY for mass produced products. (We know that the LM5101 status is NRND.)
Occasionally, when VDD exceeds 13V, the HO pulse is output thinner than the HI pulse.
Is this phenomenon a specification? Is there a description in the data sheet?

Regards,
ACGUY

  • Please let me add a question.
    Will the LM5101 stop if an overcurrent is output from the HO port?

    Best regards,
    ACGUY

  • Hello ACGUY,

    Looking at both questions, previous post and this one. The LM5101 does not specifically have a current limit function on the driver outputs. The driver provides a typical 1A peak drive current and the driver output stage is inherently limited in the maximum current that can be sourced or sinked.

    On the other question. Can you describe the change you are seeing with output pulse width relative to VDD? We may expect some change in propagation delays with different VDD level as the device delays and internal logic usually has a trend of slightly longer delays with lower VDD. This could result in some change in the input pulse width to output pulse width, but I would not expect a significant change in output pulse width.

    If you are looking at the MOSFET Vgs, or there is no gate resistance in the driver output, you may be seeing the effect of the driver having higher drive strength with higher VDD. This may result in slight driver output pulse widths when driving a load.

    Confirm if this addresses your questions, or you can post additional questions on this thread.

    Regards,

  • Hello,

    Thank you for response. I got waveform from customer, I want to do send it you on private message. Can I apply a friendship?

    Regards,
    ACGUY

  • Yes you can friend me to have conversation off of the public forum, for sharing private information.

    If you have any issues let me know and I can look to do the same.

    Regards,

  • Hello,

    I borrowed the LM5101 from a customer and obtained waveforms.
    When VDD rises above 13.5V, the output pulse becomes thinner than the input pulse.
    I think that this operation is not normally. Could you explain about cause for it?

    Regards,
    ACGUY

    LM5101 High Side Only.pdf

  • Hello ACGUY,

    We're reviewing and will get back to you promptly.

    Regards,

    -Mamadou

  • Hello ACGUY,

    I sent you a friend request so that we can more effectively work this issue in an offline conversation. Confirm if you see the friend request and send a private message. Or if there is an issue, request to friend me or comment on this thread.

    Regards,

  • Hello ACGUY,

    I sent you a friend request so that we can more effectively work this issue in an offline conversation. Confirm if you see the friend request and send a private message. Or if there is an issue, request to friend me or comment on this thread.

    I am going to go ahead and mark this thread as resolved and close as we take the conversation offline.

    Regards,