Can you explain Power-Off protection and its benefits?

Document created by analog-archivist Employee on Feb 23, 2016
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Can you explain Power-Off protection and its benefits?


The ADG5248F will provide protection to downstream circuitry against
over-voltage conditions when it’s unpowered. This is very important for modules
that may be unpowered but have signals present on the inputs.  Power-off
protection to down-stream circuitry cannot be guaranteed using discrete
protection components. 

The ADG5248F Power Off protection guarantees the channel will remain in the OFF
state and will Standoff up to ±55V i.e. no signal will get passed to the output
protecting downstream components.  On the ADG5248F, the supplies can be
grounded or floating but GND must be present on the GND pin for the Power-Off
function to work.  If the supplies are grounded during  Power-Off you will get
~500nA of leakage on the output and if the supplies are floating the leakage
peaks to about 50uA.