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    measuring the parasitic capacitance at a certain node in cadence

    is it possible to measure the parasitic capacitance at a certain node in a schematic in cadence??

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    Re: measuring the parasitic capacitance at a certain node in cadence

    Yes, it is.



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    Re: measuring the parasitic capacitance at a certain node in cadence

    Quote Originally Posted by amr.maghraby View Post
    is it possible to measure the parasitic capacitance at a certain node in a schematic in cadence??
    I don't know what you want to mean by "in a schematic in cadence" at all.

    However Synopsys HSPICE have following.
    Code:
    .OPTION CAPTAB
    Adds up all the capacitances attached to a node and prints a table of singleplate
    node capacitances.
    Syntax
    .OPTION CAPTAB
    Default 0
    Description
    Use this option to print a compiled table of single-plate node capacitances for
    diodes, BJTs, MOSFETs, JFETs, and passive capacitors at each operating
    point.
    Note:
    When .OPTION CAPTAB is used to estimate the equivalent capacitance of
    the circuit nodes, HSPICE can give a zero capacitance values for some
    nodes when a resistance is connected to that node. The reason for getting
    0 is that the capacitance is a dynamic, frequency-dependent capacitance
    and not a static capacitance. You need to run an AC analysis to see a nonzero
    node capacitance.
    Cadence Spectre also have similar ability.
    https://www.edaboard.com/showthread.php?380999
    Last edited by pancho_hideboo; 17th June 2019 at 18:01.



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    Re: measuring the parasitic capacitance at a certain node in cadence

    Quote Originally Posted by Dominik Przyborowski View Post
    Yes, it is.
    can you please tell me how to find the parasitic capacitance in cadence IC 6.1.3

    - - - Updated - - -

    Quote Originally Posted by pancho_hideboo View Post
    I don't know what you want to mean by "in a schematic in cadence" at all.

    However Synopsys HSPICE have following.
    Code:
    .OPTION CAPTAB
    Adds up all the capacitances attached to a node and prints a table of singleplate
    node capacitances.
    Syntax
    .OPTION CAPTAB
    Default 0
    Description
    Use this option to print a compiled table of single-plate node capacitances for
    diodes, BJTs, MOSFETs, JFETs, and passive capacitors at each operating
    point.
    Note:
    When .OPTION CAPTAB is used to estimate the equivalent capacitance of
    the circuit nodes, HSPICE can give a zero capacitance values for some
    nodes when a resistance is connected to that node. The reason for getting
    0 is that the capacitance is a dynamic, frequency-dependent capacitance
    and not a static capacitance. You need to run an AC analysis to see a nonzero
    node capacitance.
    Cadence Spectre also have similar ability.
    https://www.edaboard.com/showthread.php?380999
    i have connected a circuit in cadence and i want to know the value of the parasitic capacitance at this node
    my question is wither there is an analysis that could give me the value of the parasitic capacitance at this node?



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    Re: measuring the parasitic capacitance at a certain node in cadence

    If you include adding minor schematic mods, then I prefer
    to add a shunt pulsed current source, who can inject a
    known small charge (large enough to be seen, small enough
    to be small-signal-ish) and look at the node step voltage
    right at the end of the pulse. Q=CV.

    Any "on" elements will steal from step voltage and you may
    want to apply a little work at determining what went to R
    and what went to C.



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    Re: measuring the parasitic capacitance at a certain node in cadence

    Quote Originally Posted by amr.maghraby View Post
    i have connected a circuit in cadence
    What do you want to mean ?
    Describe correctly with correct terminology.

    If you use Cadence Spectre, use "info what=captab" analysis in Cadence Spectre.

    Surely see https://www.edaboard.com/showthread.php?380999


    1 members found this post helpful.

  7. #7
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    Re: measuring the parasitic capacitance at a certain node in cadence

    What would you like to do?
    1. Simulate capacitance at specific node?
    2. Extract capacitance for all nodes?
    3. Read parasitic capacitance from extracted view?
    What views you have?
    What tools you have?



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  8. #8
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    Re: measuring the parasitic capacitance at a certain node in cadence

    Mandatory reminder that Cadence is a company. There is no tool called Cadence...
    Really, I am not Sam.



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