> > The 1640 has variants which are not available in the 1623/24
> > which instead of turning off the PFEt in disable mode, turn it hard
> > on. This allows the battery to be connected to the output in
> > shutdown. If Vin is high enough this is most useful

Quick answer to what I think the question is from what I recall the
datasheet said. The following or the correct version thereof is in the
datasheet.

"Pass through when off" version will allow straight through operation
as you describe. It will turn the converter on when the enable line
goes high.

When the enable line is low the device looks like an on PFET in series
with battery. At this stage the device drwas 1 uA. Current able to be
drawn is probably limited by PFET rating. 500 mA or 800 mA or
whatever. See datasheet. PFET needs no drive current, being a FET.

When converter is running but unloaded the current drain is typically
14 uA (from memory). This is perhaps at 3V3 or whatever but will
probably be similar regardless. Any load adds to this.


 Russell
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