ADUM1251/ADUM1250 Isolation

I am investigating the ADUM1250/1251 devices for an I2C isolation application.

My concern is that it appears both VDD pins are considered to be supply pins because the datasheet lists a sink current for both VDD1 and VDD2.  If both pins are sinking current and powering the device, will the device still be able to provide isolation on the power rail?

Also, we plan to use the chip to prevent latchup when hot plugging a non-powered device into a powered device.  Will the ADUM1251 need to place on the non-powered device or the powered device?

Thanks in advance.

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    •  Analog Employees 
    on Feb 2, 2012 7:15 PM

    Hello jocruz,

    the ADuM1250 does not isolate the power supply.  The chip can be thought of as two seperate devices that communicate with each other through pulse transformers.  Power must be provided to each side seperately.  We do have a line of chip scale DC/DC converters that can be paied with the ADum125x to provide power from one side of your application to the other.  Look at the ADuM5000, it can producs up to 100mA of isolated power at about 33% efficincy.

    MSCantrell

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  • 0
    •  Analog Employees 
    on Feb 2, 2012 7:15 PM

    Hello jocruz,

    the ADuM1250 does not isolate the power supply.  The chip can be thought of as two seperate devices that communicate with each other through pulse transformers.  Power must be provided to each side seperately.  We do have a line of chip scale DC/DC converters that can be paied with the ADum125x to provide power from one side of your application to the other.  Look at the ADuM5000, it can producs up to 100mA of isolated power at about 33% efficincy.

    MSCantrell

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