At 10:19 PM 6/16/00 -0400, Bob wrote:
>1: where can I get a brief synopsis of the various logic families now
>available.
>
>2: what family/families are best for general purpose digital design -
>especially around a PIC (this is the PICLIST!).

The Radio-Shack commercial catalog has quite a bit of technical information
in it, including a full page comparison of digital logic families and their
specs.

I'm no heavy user, but I use the CD4xxx when I don't need speed (e.g., 1
MHz or less) and 74HCxxx when I do. The 74HCTxxx is useful when you need
tighter TTL capatability (which I normally don't) or more output current.

The advantage of the CD4xxx is the wide range of supply voltages possible.
The 74HCxxx is much narrower, although I've inadvertently run some at 15V
with no apparent harm.

Any other CMOS families besides these three have very narrow parts
functionality. The TTL families draw more power and are more voltage sensitive.

================================================================
Robert A. LaBudde, PhD, PAS, Dpl. ACAFS  e-mail: ral@lcfltd.com
Least Cost Formulations, Ltd.                   URL: http://lcfltd.com/
824 Timberlake Drive                            Tel: 757-467-0954
Virginia Beach, VA 23464-3239                   Fax: 757-467-2947

"Vere scire est per causas scire"
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