Excellent tip, I always thought the rule resulted in a lot of wasted power and
not exactly good LP design. And if one is driving lots of pins that way the
UP has internal power rail issues, as well as the output drivers.
I am curious, I might try your method out to see how much of a power savings
it portends.
There is one problem I see, the min Hfe, or Beta, not speced in sat, so I assume
thats why you double for safety....?
Regards, Dana.