ttl ic`s

[mark krawczuk]

hi, i`m trying to build a bdm32 interface to program my saab trionic ecu ,
put the parts list is for hc ttl ic`s , i have ls ttl ic`s , are these
interchangable ?
thanks,
mark k

 

[legg]

On Thu, 31 Jul 2008 15:03:40 +0930, "mark krawczuk"
<krawczuk@adam.com.au> wrote:

hi, i`m trying to build a bdm32 interface to program my saab trionic ecu ,
put the parts list is for hc ttl ic`s , i have ls ttl ic`s , are these
interchangable ?
thanks,
mark k

HC are CMOS with different logic levels and loading capabilities. They
are proably easier to obtain nowadays than standard TTL.

RL

 

[Michael Black]

On Thu, 31 Jul 2008, legg wrote:

On Thu, 31 Jul 2008 15:03:40 +0930, "mark krawczuk"
krawczuk@adam.com.au> wrote:

hi, i`m trying to build a bdm32 interface to program my saab trionic ecu ,
put the parts list is for hc ttl ic`s , i have ls ttl ic`s , are these
interchangable ?
thanks,
mark k

HC are CMOS with different logic levels and loading capabilities. They
are proably easier to obtain nowadays than standard TTL.

From the subject header, I figured the post would be about some old

schematic that used straight TTL, while the poster wanted to use
more recent variants.

I still have some straight TTL around, but that's because when I
started with the 74XX family, TTL was the norm, with "H" and "S" sort
of there. I'm surprised that someone would have TTL and nothing more
recent lying about.

Michael

 

[legg]

On Thu, 31 Jul 2008 13:16:23 -0400, Michael Black <et472@ncf.ca>
wrote:

On Thu, 31 Jul 2008, legg wrote:

On Thu, 31 Jul 2008 15:03:40 +0930, "mark krawczuk"
krawczuk@adam.com.au> wrote:

hi, i`m trying to build a bdm32 interface to program my saab trionic ecu ,
put the parts list is for hc ttl ic`s , i have ls ttl ic`s , are these
interchangable ?
thanks,
mark k

HC are CMOS with different logic levels and loading capabilities. They
are proably easier to obtain nowadays than standard TTL.

From the subject header, I figured the post would be about some old
schematic that used straight TTL, while the poster wanted to use
more recent variants.

I still have some straight TTL around, but that's because when I
started with the 74XX family, TTL was the norm, with "H" and "S" sort
of there. I'm surprised that someone would have TTL and nothing more
recent lying about.

On another net group A.B.S.E. the OP has changed his TTL to LS TTL,

with the same basic question.

I think the answer is the same, unless he chages the CMOS end of the
equation to AC or AHC - and even then some precautions are needed.

RL