Another look at the LM319

A project log for Tern - Ternary Logic Circuits

A series of ternary logic gates and higher level components implemented in the real world.

Mechanical AdvantageMechanical Advantage 06/16/2015 at 06:310 Comments

It looks like I spoke too soon. The 319 is actually more versatile than I thought. It has an interesting arrangement for power management in that it has a Vcc connection (to +5V), a Vee connection (yep, that's for the negative voltage, -5V), and a separate ground connection for each of the two comparators on the chip. I had initially connected the ground connections to ground (duh!) but just found that I can connect them to -5V as well. When in this mode, the "low" signal is now -5V instead of 0V. Further, when in this mode, I can now connect the open collector output to 0V reliably and the high signal becomes 0V instead of 5V. All of the sudden the LM319 looks like it can do everything the 393 could do and then some. Here is the enumeration:

With the ground pin attached to 0V, the 319 can provide these ternary monadic functions with a single comparator: E, H, R, and X.

With the ground pin attached to -5V, the 319 can provide these ternary monadic functions with a single comparator: 1,2,4,8,9,C,K, and V. These are hooked up exactly the same way as the diagram supplied for the 393.

When you take into account the three trivial functions (0,D, and Z) that are merely connections to the appropriate power rail, the LM319 can provide 15 of the 27 possible monadic functions with only one of its two comparators.

Adding to the awesomeness, the two comparators in the package have their own separate GND connections which means they can each be arranged separately for even more versatility.