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    I/O pad simulation : calculation of drive current ,pull-up and pull-down resistances

    What is drive current for a PAD and how to decide drive current for I/O PAD while doing characterization.Also how to calculate the pull-up and pull-down resistance for I/O pad cells.

    Thanks

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    Re: I/O pad simulation : calculation of drive current ,pull-up and pull-down resistan

    Quote Originally Posted by dileep4111 View Post
    What is drive current for a PAD
    The current which can be driven by the output buffer of the pad.

    Quote Originally Posted by dileep4111 View Post
    how to decide drive current for I/O PAD while doing characterization.
    While doing characterization you measure - you can't decide on your results (just if they are reasonable).

    Quote Originally Posted by dileep4111 View Post
    how to calculate the pull-up and pull-down resistance for I/O pad cells.
    Depends on requirements (customer's or yours).


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    Re: I/O pad simulation : calculation of drive current ,pull-up and pull-down resistan

    How should i characterize the drive current of pad. Currently i am using Spectre tool from cadance.
    thank you



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    Re: I/O pad simulation : calculation of drive current ,pull-up and pull-down resistan

    Which type of pad? Analog or digital? Output only or I/O pad?



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    Re: I/O pad simulation : calculation of drive current ,pull-up and pull-down resistan

    It is I/O PAD



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    Re: I/O pad simulation : calculation of drive current ,pull-up and pull-down resistan

    Quote Originally Posted by dileep4111 View Post
    It is I/O PAD
    Again: Analog or digital? Provide its schematic!

    BTW: Slowly I'm running out of endurance, if you're not even willing to provide the info necessary to be able to respond to your questions!
    Last edited by erikl; 2nd April 2013 at 15:59. Reason: amendment



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    Re: I/O pad simulation : calculation of drive current ,pull-up and pull-down resistan

    It is a bidirectional Digital PAD from TSMC



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    Re: I/O pad simulation : calculation of drive current ,pull-up and pull-down resistan

    So why don't you simply have a look into the respective TSMC Standard I/O Lib Data Book? E.g. this one: Click image for larger version. 

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    If you rightfully got the schematic and/or layout of the cell, you'd have access to it, too. There you can find the drive capabilities:
    Pls. notice the correlation between a part of the cell name and its drive capability!


    If you want to simulate: Enable the output, set a logic input voltage, measure the output current, either in short circuit mode, or into a known output load up to your requirement. Repeat this for the other logic input voltage.

    Hope this helps!


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