gene heskett wrote: > > But there are still plenty of the older TTL stuffs gathering dust on the > shelves at Newark et all. The advantage of CMOS is to me, the much larger > noise immunity. Running on 5 volt rails, noise has to be nearly half that > 5 volts in order to even get into the active regions of the logic. TTL only > needs about .6 volts of noise to get into the active area if the total > swing, which running on 5 volts is from .1 volts for a zero, and about 3.1 > volts for a logic 1 when loaded to its rated fanout. Typical guaranteed > logic zero might extend as high as .6 volts, and logic 1 is guaranteed only > for inputs above 2.4 volts. > > Yes, in some cases a pull-up resistor can help greatly with noise immunity. But, I sure hope I never order something from Newark and get a 30-year old part!
Jon ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ Emc-users mailing list Emc-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/emc-users
