14606Re: [cosmacelf] IC Date Codes
- Dec 14, 2013
74H was higher threshold and power for improved noise margins compared the plain 74.
74L and LS were lower power than 74.
74S and later AS then F then AF were faster, faster, faster...
Then the CMOS generation , 74C, HC, HCT, and likely others...
The biggest thing to watch for is family to family incompatibility.
The OLD 74C would not work with most Bipolar TTL without pullups.
74S and 74LS didn't get along well without watching fanout and fanin
as 74S could pull down well but LS could not pull the higher current
inputs down well.
I worked with all of them and have large samples of most.
- << Previous post in topic Next post in topic >>