Counter/Timer

cancel
Showing results for 
Search instead for 
Did you mean: 

Can the TTL inputs of my 6602 be damaged by low but negative voltages?

I am interested in using the counters of my 6602 board to measure the frequency of a sine signal. I could convert the signal to a TTL compatible pulse signal, but was wondering whether I could simply hook up the signal without doing this. The input voltages would be low (<4V pk-pk), but I seem to recall that TTL inputs can be damaged if the voltage goes negative. Would it damage the board to try this?
0 Kudos
Message 1 of 3
(3,947 Views)
Hello Travis,

National Instruments does not recommend giving an input voltage less that -0.3V. How much less can the board can take is another question and it might vary. I would not try any voltage less than -.3V

Arun V
0 Kudos
Message 2 of 3
(3,947 Views)

Hello there ... though this thread is quite old ...

 

I am doing the same, using a 6016 DAQ and a pulse generated through a schmitd trigger from a sinewave

 

I get a peak negative voltage of -0.3 V and it works fine and the limit in the NI6016 is 0V. In the 6602 it is -0.3V, so therfore you should not have much trouble.

0 Kudos
Message 3 of 3
(3,541 Views)