CMOS (4000B) compared to TTL Low power Shottcky (74LS)??


Hello all,
I am studying electronics at college and have been asked to compare the TTL Low Power Schottky (74LS) and CMOS (4000B) logic families.
I have searched the internet for figures to compare but it seems that everywhere I look gives different values for the specifications that I require. Would any of you be able to give me general values for the:

-Logic high and Logic Low Input current and ‘Fan In’

-Logic high and Logic Low Output current and ‘Fan Out’

-Propagation Delay

-Noise Margin

-Logic high and Logic Low input voltage levels

-Logic high and Logic Low output voltage levels

-Upper frequency limit

for each of the TTL Low Power Schottky (74LS) and CMOS (4000B) logic families so that I can then compare them to each other to create my answer.

I understand these values may be slightly different for different logic chips and manufacturers but I am just after a general overview. Component datasheets don’t seem to give all the information that I require and they are all rather cryptic about some points as I guess these values are presumed by the fact they are members of these logic families.

Any help would be amazing.



Hello @Millertron,

Take a look at these links.
4000B and 74LS

Just looking at the product attributes for each of the families will help with many of the available differences. You can generalize what is available between the two families as both will have a range.

Ti has an excellent logic Guide that may help looking at the general difference in noise and freq that is harder to decipher from the data sheet. Take a look here.

If you have any specific part questions that i can help answer please let me know.