Re: A strange problem with CMOS Up/Down counter

csl wrote: 
Hey all,

Been searching for topics relating to what I have been experiencing and
to no avail.

Hopefully some of you might have a hint or tip. I am using a TI
CD40110B CMOS Up/Down decade counter. It has a separate clock up and
clock down. I connected to a Kingston 7-segment LED and here's what I
have been observing:

1. Counting up from 0 to 9 is ok.

2. Counting from 0 to 1 to 2 to 3 back to 2, when clock up is activated
nothing happens. When activated AGAIN, it jumps to 3.

3. Counting down from 9 to 2 to 3 then back to 2. Then clock up is
activated, nothing happens. When activated again, it jumps to 3.

I can't seem to figure out what's the problem. It only happens when one
returns from 3 to 2 and making an attempting back to 3.

If you have any suggestion, please post. Thanks for reading.


I would check the clock polarity. Make sure that the unused one is not left in its active state when clocking.

--
Luhan Monat (luhanis 'at' yahoo 'dot' com)
"The future is not what it used to be..."
http://members.cox.net/berniekm
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