whats the diff/ CHIPS

[RX5]

between SN74xx and SN74LSxx ??

[GlennS]

between SN74xx and SN74LSxx ??
One is TTL and the other is low power Schottky.
glenn.

[jeffs555]

They will generally have the same function and pinouts, but have different current requirements and different speeds. Generally, 74LSxx is slightly faster than 74xx and consumes much less current. 74LSxx has less output drive current, but also has less current demand on the inputs.

There are lots of other 74xx logic families with the same function and pinout but different currents and speeds and some have different voltage specs. 74Sxx, 74Fxx, 74HCTxx, 74ACTxx, 74ALSxx and so many more I can't keep up with them all.

[RX5]

They will generally have the same function and pinouts, but have different current requirements and different speeds. Generally, 74LSxx is slightly faster than 74xx and consumes much less current. 74LSxx has less output drive current, but also has less current demand on the inputs.

There are lots of other 74xx logic families with the same function and pinout but different currents and speeds and some have different voltage specs. 74Sxx, 74Fxx, 74HCTxx, 74ACTxx, 74ALSxx and so many more I can't keep up with them all.


thanks... yeah LS is [L]ow power [S]chottky... was planning to bulid the digital commander using SN7490 & SN74145... cant find chips here without the "LS" so I bought chips with "LS".... so I guess this is pretty OK since it does NOT have to drive big currents, just -small- signals...

[westfw]

Note that these days, both 74xx and 74LSxx bipolar logic families are essentially obsolete. They've been replaced with assorted CMOS families (74ACxx, 74HCxx) with higher speeds, (vastly) lower power consumption, and (mostly) similar drive capabilities.