HCT vs LS..

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I've got a circuit specifying a "74HCT138" and can find a 74LS138 at Jaycar,
is this a compatible component?

Thanks in advance!



Re: HCT vs LS..


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The HCT is CMOS and the LS isn't, there are differences
in speed, voltage levels and power consumption. You can
try it but it maybe erratic

Re: HCT vs LS..



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**Same basic function, but fundamental differences in performance. Best not
to substitute, unless the circuit is uncritical.


--
Trevor Wilson
www.rageaudio.com.au



Re: HCT vs LS..


Thanks to both who replied :)

I'd guess timing probably ISNT too criticial, but for the sake of a day or
2, i'll order the correct parts from farnell :)

Thanks again!

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Re: HCT vs LS..


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For all but the most critial aplication they should be compatible,
although usually it's the other way around. The HCT series is designed
to be a low power high speed CMOS replacement for the 74LS series, as
it has TTL compatible voltage levels, that's what the "T" stands for.
Best to get the same part if you can though, substituting parts may
work at first try, but unless you try it over the full performance
envelope you won't really know.

Dave :)


Re: HCT vs LS..


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sometimes. google for the specifications.




--

Bye.
   Jasen

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