Spehro Pefhany wrote:
> Do you *really* need to lock it out for seconds? A shorter time, such 
> as 100msec would be a lot easier-- just a pot + R from OCDa to 
> discharge aceramic cap of say 47nF and (eg. 100R pot + 10R) and charge 
> the cap through a 2M resistor to Vdd. That would give you a lock out 
> time constant of about 100msec, and a trigger time constant of about 
> 5usec +/- 2usec. No active parts at all.
The problem seems to be that 100msec is too low...  The part will self 
destruct with a 22uf /22K combination after 5-10 seconds when dealing 
with a dead short.   I would expect that the times with a 47nf/2M 
pair+~110on OCDa (dead time of about 1/5 of the 22uf/22K pair) to be 
even more dismal from my testing.   The 22uf seems to be about the 
smallest cap I could deal with unless I added a R to OCDa, in which case 
it basically permitted me to use a smaller cap, but with the same effects.

I think I'm actually at the point of saying "trigger the overcurrent 
detection, game over, require power cycle"... which might be easier to 
deal with, since a short should never happen, and if it does, requiring 
a human to figure out why is probably a good thing.

-forrest
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