fachat wrote:
I got the end-of-life notification for some TI parts like this...Would 74AHCT work?
74AHCT may be considered a direct replacement for 74HCT in almost any application. 74AHC(T) is essentially a combination of the propagation speed of 74AC(T) and the lower drive and less-aggressive edges of 74HC(T). Most 74AHC(T) parts have nearly-identical prop times as their 74AC(T) equivalents (many 74AC(T) gates run in the single-digit nanosecond range), so there will be a substantially boost in the maximum speed at which a given circuit could be run. 74AC(T) devices typically can source/sink 24 mA, whereas the 74AHC(T) family can source/sink 8 mA, so that characteristic, along with the slower edges, gives some relief from ringing problems—theoretically, things will be no worse than with 74HC(T).
I suspect 74AC(T) logic will gradually disappear, other than bus drivers and transceivers, with which the strong output drive is generally a desirable characteristic. Other than bus drivers, I see no reason to not use 74AHC(T) in place of 74HC(T), even in applications in which prop times are unimportant.
Many, but not all, 74AHC(T) devices continue to be available in PDIP, with SOIC a practical alternative if the builder is able to solder packages with 50-mil pin pitch.
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