switches electronic model

sir:

   ADI do not provide spice model for switch ADG5412. But the "off isolaltion" characteristic of ADG5412 is a main problem that exist in my design. So I want to do some simluation about ADG5412.  I have a few question that need to be answered first before my simulation.

(1) When the switch is in off state,  there are parameters Cd(Off),Cs(Off). What does Cd and Cs stand for? what is the capacitance bewteen

Drain and Source? Is the Cds equal to the sum of Cd and Cs?

(2) What is the electronic model when the switch is in off state? If we assume off resistance is infinite, can we think that the electronic model of the switch is a capacitance with value equal to  Cds?

Thanks!

Regards

Jacky

2012-11-15

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  • 0
    •  Analog Employees 
    on Dec 4, 2012 7:11 PM

    Hello Jacky,

    We don't measure or specify Cds, but this can usually be approximated by subtracting the Cs(OFF) and Cd(OFF) from the Cds(ON).

    These specifications are usually typical values and this method has better results with the ADG12xx series of parts which are given maximum specifications for the capacitances.

    Regards,

    Sean

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  • 0
    •  Analog Employees 
    on Dec 4, 2012 7:11 PM

    Hello Jacky,

    We don't measure or specify Cds, but this can usually be approximated by subtracting the Cs(OFF) and Cd(OFF) from the Cds(ON).

    These specifications are usually typical values and this method has better results with the ADG12xx series of parts which are given maximum specifications for the capacitances.

    Regards,

    Sean

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