wire ORed

Wendy

Joined Mar 24, 2008
23,415
It has to do with open collector outputs. If you tie a bunch of collectors together sharing one resistor it is equivalent to an OR gate. It was a common practice in the days TTL logic was king.
 

beenthere

Joined Apr 20, 2004
15,819
To expand a bit on Bill's post, those open collector outputs are all pulled up with a single resistor. Thus any one output can pull the common line low.
 

beenthere

Joined Apr 20, 2004
15,819
It has an open collector output - the second paragraph of the intro on the data sheet stated that the device can be wire OR'ed. Open collector outputs are open collector outputs.
 

leftyretro

Joined Nov 25, 2008
395
And of course wired OR can be accomplished by using series diode isolation between each of the 'voting' nodes and a single pull-up resistor so having open collector outputs is not the only way to be able to utilize wired OR stages.

Lefty
 
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