Help me choose between two different XOR units?

Question

I will be controlling the inputs of these XORs directly from a PIC
output, both PIC and Logic powerd from the same regulated +5V. I have
two choices:

ST's Single XOR 74V1G86STR in a SOT23-5L
http://www.st.com/stonline/books/pdf/docs/5735.pdf

OR

Fairchilds Tinylogic UHS Single XOR NC7SZ86M5X in a SOT23-5L
http://www.fairchildsemi.com/ds/NC/NC7SZ86.pdf

They are both astonishingly similar:
both have a VIH minimum of .7 @ 5V
both have a VIL maximum of .3 @ 5V

The Tinylogic can provide up to -+ 24mA at output
The ST can provide a minimum of 8 mA at output

The XOR's output is directly connected to the two Reset pins on a 556.
Hence when the XOR goes high, the 556 begins oscillating. When the XOR
output goes low, the 556 goes back down to outputting 0V.

rscanner, the PIC is pre-programmed. I dont have acess to a PIC programmer

Answer 1

What you didn't say is why you are using an XOR when you have a PIC? Unless there are speed or other issues all logic should be done in the PIC. Then just one lead to the 556 timer. In fact why have a 556 timer? Just use the PIC to produce the same output as the 556 timer.....

Answer 2

I've used both and I can't tell any difference at all between them. Since you're driving the input(s) of a 556 you don't need to worry about current sourcing, so it really doesn't make any difference which one you use.


Doug

Answer 3

I don't have the pricing and datasheets. But i am guessing they have the same pin out. If so, it doesn't matter. Go with the cheapest one.

But I personally prefer to use a higher current driver for the application you mentioned, if the price is the same.

Answer 4

frst 1

Answer 5

Same as rscanner