Mike Harrison wrote:
> Use HCMOS instead - LSTTL is completely obsolete, as HCMOS
> is better in all respects (speed, power, cost).

Is that so ?
Power yes, cost maybe, but speed ?

From what I'v seen bipolar 74xxx is still faster then CMOS 74xxx.

From the "Texas Digital Logic Pocket Data Bbook" :

74xx00, switching time (low to high):

7400    :  22   ns
74LS00  :  15   ns
74ALS0  :  11   ns
74AS00  :   4.5 ns
74F00   :   6   ns

74HC00  :  25   ns
74HCT00 :  30   ns
74ACT   :  12.3 ns

Jan-Erik S=F6derholm

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