ADG751 Source isolation

Hello, 

I want to use ADG751 switches for a circuit I am working on. My switches in this circuit are floating (sources are not grounded), will be this a problem using ADG751 CMOS switches? Also, I am driving the gate(switch on and off in high speed around 1MHz) using a microcontroller, do I need to have an isolation for the floating source?  or I need a bootstrap circuit to ensure turning the switches on & off ?

Thanks

Jacob

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    •  Analog Employees 
    on Feb 27, 2017 2:25 PM

    Hi Jacob,

    The signal presented to the source/drain of the ADG751 needs to be between -0.3V and VDD + 0.3V so that the absolute max ratings are not violated. The absolute max ratings are referenced to the GND of the device so if the voltage source is floating you would need to be able to guarantee that the input voltage max range is not violated.

    The digital logic input high and input low voltages are also referenced to the GND of the device so the logic input signal needs to be 2.4V above the device GND for the switch to turn on.

    Regards,

    Stephen

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  • 0
    •  Analog Employees 
    on Feb 27, 2017 2:25 PM

    Hi Jacob,

    The signal presented to the source/drain of the ADG751 needs to be between -0.3V and VDD + 0.3V so that the absolute max ratings are not violated. The absolute max ratings are referenced to the GND of the device so if the voltage source is floating you would need to be able to guarantee that the input voltage max range is not violated.

    The digital logic input high and input low voltages are also referenced to the GND of the device so the logic input signal needs to be 2.4V above the device GND for the switch to turn on.

    Regards,

    Stephen

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