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ADuM1401 output drive

Can anyone clarify what ADuM1401 side 1 drive value is? The data sheet tells only Absolute Maximum Ratings:

Average Output Current per Pin -18mA to + 18 mA

There are two ways to read this:

average/pin (3 outputs on this side) is max. 18 mA, total 54 mA OR

max. for each 18 mA in averaged in time.

Then there is a table of max. supply/side but this is much higher and contains dynamic part.

What will happen in time if one is loaded with 20 mA and other two have no load?

Jouni

  • Hi Jouni:

    +-18mA is the current limit from safety requirement which means the maximum allowed current flow when a isolation failure happens.

    the suggested load current limit is 4mA.

  • I did not find anywhere mentioned operational limit. This 4 mA was mentioned where the voltage drop/rise was specified at some currents. Typically max. usable current would be half from absolute max. ratings but the voltage levels would suffer. If we don't care about the voltage drop or speed is there any other reason to drive say 10mA? Also, this is on 'inside' part of design so we try not to have to add buffers to drive this 10mA/side.