Hi all,
I have designed and built a circuit using a CD40193 to be an 8 bit up counter. The MSB (J4) resets the clock. This counter runs up to 16 MUX's (MAX4598) and 4 DEMUX's (MAX5166). I am able to vary the # of MUX's in the system, but not the # of DEMUX's.
The problem I have is that with 8 MUX's the system works as expected. When I jump to 10 or more MUX's, I get noise. I have tracked the noise down the the up counter, and more specifically the J4 - reset pin. This pin will phase shift about 90 degrees, producing noise in the system. If I cool the part down, the noise goes away until the chip heats up again. Any thoughts on this?
Thanks,
Mike
