Replacement for a DEC 7474 Chip

Chuck Guzis cclist at
Sun May 15 09:57:13 CDT 2022

On 5/14/22 23:04, ben via cctalk wrote:

> Faster is not better, bigger is bett... ops wrong topic.
> 74H while slower, and 74S tend to have reliable delay times looking at
> gates with min to max delays < 3 ns. This helped devices to track
> the same speed across a system.
> A 74ABT00 is 1 to 4 ns depending on the temp,phase of the moon,and what
> ever. How much margin do I need to add? Ok I guess for connecting a 386?

Sure, but if the concern was output sink current, the S or AS family can
certainly provide it.  It all depends on the position of the IC in the
circuitry.   Depending on application, you might conceivably get away
with a 74HC74; that is some parameters may not matter.   I might still
have a couple of DM7474's kicking around, but they're so old, I wouldn't
depend on them.   I even have a few Fairchild 74F74s...


More information about the cctalk mailing list