Re: A few novice questions

In article <a0026cdb-aea2-40e3-b0f0-
095c648e447e@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>, Tomás Ó hÉilidhe says...
On May 2, 8:52 pm, larwe <zwsdot...@xxxxxxxxx> wrote:
1) What kinds of chips I should use with it, e.g. 74HCT family, or
4000 family, etc. ?

Selecting an external logic family depends on your circuit's Vcc, the
I/O level (CMOS, TTL, etc), the switching speed, the power consumption
etc. Many (I would guess most but I'm not sure about that) embedded
systems use no external discrete logic at all.


One of my lecturers told me today that 74HCT hasn't been used for
about the last 10 years, and that the 4000 family hasn't been used
since maybe the 60's.

That seems a rather odd assertion.

So now I'm wondering what family of logic chips are actually being
used *today* in conjunction with today's microcontrollers, e.g. the
PIC16F684?

If I had to use a PIC of any sort and I needed an external logic source
my first choice would be an HCT device. Most of the faster types (at
least as far as I've seen) appear to be limited to commercial
temperature range. Besides why would you need faster to interface with
a PIC?

Robert
** Posted from http://www.teranews.com **
.