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.
Re: Einsteins Doppler equation wrong? ... :> CMOS... : you went with TTL.... :> and the edges on the CMOS chips were blazingly fast compared to ... that showed a Pentium on the back of a snail, that said, "Think ... (sci.physics.relativity)
Re: Einsteins Doppler equation wrong? ... > CMOS... you went with TTL.... >: TTL chips.... The fastest garden variety chips in the 90's, as I recall, were BiCMOS or ... (sci.physics.relativity)
Re: Choice between CMOS 4099 or 74HC259 ...Plain TTL, or even LS TTL is as old and outdated as 4000 CMOS and they chew ... >No, the 4099 would drive just LEDs, up to eight, one per output. ... >I've hooked up an LED to a CMOS output in the past (with resistor) and ... (comp.arch.embedded)
Re: Problems understanding pin connections ... Can anyone direct me to a good guide which explains the differences between ... "Push-pull" -- Actively supplies current from VCC to pull the voltage up, and pulls current to VEE to pull the voltage down. ... In addition to this you need to pay attention to old-style TTL logic interfaced to CMOS: a 5V TTL part is only guaranteed to drive about 2.7V or so as a "high", which is less than what 5V CMOS is guaranteed to respond to. ... (comp.arch.embedded)
Re: CMOS logic, efficiency versus frequency? ...TTL and ECL are nice and warn even when they are not ... > toggling.... Leakage is a huge deal in high-end CMOS these days. ... > ECL has a non-switching loss about the same as its high frequency loss.... (sci.electronics.design)
