Ref Pin Voltage range

Hi ADI,

AD620 has specifications for allowable operating voltage range for the VREF pin - presumably for it to function properly, however it does not have specifications for absolution maximum range or range of voltages allowed when the part is powered down that the circuit must remain within in order to prevent damage or stress to the part.  In my application I need to apply a reference voltage to the AD620's REF pin that not derived from the AD620's power rail and I need to understand the sort of safeguards I have to put in place as currently the REF pin could be powered while the AD620 's supply is powered down.

Please let me know if you have any questions or need further from me to answer this question. 

Thanks,

Max