Why is TTL so expensive?

kstillin

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man-

I'm looking for some 74s163n chips for a System I board, but the only ones I find are $3-$4 EACH!!

Didn't this crap used to be less than a buck? Hell- I always thought they were PENNIES per chip. I guess it's just that as time marches on, the technology becomes obsolete and nobody manufactures it anymore.

But I mean -damn. You can buy Z80's and modern microcontrollers for less than that...

any links to cheaper chips would be appreciated.
 
Im showing 50 in stock.
http://store.pacmandotcom.com/searc...esc&search_query=74ls163&submit_search=Search

Yeah, $3-$4 is ridiculous for sure. But your also right about obsolete chips becoming hard to find and expensive. TTL is still easy to come buy for most of them. The problem is alot of the older obsolete stuff is getting recycled for precious metals.



Other options
http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=296-3661-5-ND

http://www.mouser.com/ProductDetail...=sGAEpiMZZMutXGli8Ay4kP28D9wZ8SQIYBOJcN9VYdk=

http://www.jameco.com/webapp/wcs/st...amecoall&ddkey=http:StoreCatalogDrillDownView
 
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Wow- big difference!

But I'm not sure if the LS series can be used in place of the S series. The specs say the S ones are faster access. These will be used on a System I motherboard. They're in the horizontal line buffer, so I would guess that speed matters in this case.


The schematic package shows many chips with the LS designation, but specifically shows these with only the 'S'. Comparing to another motherboard, there are 'S's in these locations there also.

Hell- I don't even know if this will solve anything. This is just a motherboard I've got that has empty sockets at these locations. I wanna fill 'em and see what I get.

Kerry
 
Wow- big difference!

But I'm not sure if the LS series can be used in place of the S series. The specs say the S ones are faster access. These will be used on a System I motherboard. They're in the horizontal line buffer, so I would guess that speed matters in this case.


The schematic package shows many chips with the LS designation, but specifically shows these with only the 'S'. Comparing to another motherboard, there are 'S's in these locations there also.

Hell- I don't even know if this will solve anything. This is just a motherboard I've got that has empty sockets at these locations. I wanna fill 'em and see what I get.

Kerry


Often they aren't going for the speed as much as the current drive of the part. The LS parts cannot drive much current but the "S" (and newer, replacement "F") parts can drive far more current.

Ed
 
man-

I'm looking for some 74s163n chips for a System I board, but the only ones I find are $3-$4 EACH!!

Didn't this crap used to be less than a buck? Hell- I always thought they were PENNIES per chip. I guess it's just that as time marches on, the technology becomes obsolete and nobody manufactures it anymore.

But I mean -damn. You can buy Z80's and modern microcontrollers for less than that...

any links to cheaper chips would be appreciated.


Plain TTL, 'LS' TTL and 'ALS' TTL isn't much in demand anylonger. Low demand means fewer are made = higher prices. A few years back, I was buying cases of new Texas Instruments (TI) SN7404N's at $0.05 each. TI now lists them at $1.30 per 1K units.

Logic isn't the only thing doing this. Just try buying a new National Semiconductor LM323K voltage regulator. These were about $2 each... now above $20 each. And far worse if you want the LM323AK. Fortunately, the ST parts are still reasonably priced...for now.

Ed
 
man-

I'm looking for some 74s163n chips for a System I board, but the only ones I find are $3-$4 EACH!!

Didn't this crap used to be less than a buck? Hell- I always thought they were PENNIES per chip. I guess it's just that as time marches on, the technology becomes obsolete and nobody manufactures it anymore.

But I mean -damn. You can buy Z80's and modern microcontrollers for less than that...

any links to cheaper chips would be appreciated.

Use the newer replacement -- SN74F163AN. $0.55 at Mouser

Ed
 
Some of the 74xx series chips are expensive...

74LS491 for example...

Also the fuse link PROMs... and the bipolar RAMs.

It all depends on if they are being made any more and what the supplies are like. Some have simply dried up.

Some of the older chips are pure unobtanium now.

It's not 74xx series, but I picked up 12 of the 25LS2519 chips and paid a small fortune for them. I looked all over to find these 12.
 
Why do you say that? For IC's I've had nothing but good experiences.

I've stopped using Unicorn....unless I have no other (reasonable) option. After two separate instances of chasing my tail....from bad-out-of-the-tube parts from Unicorn, I said no more. The last time I had two tubes of LM3900s. Fighting with a Space Invaders with audio issues....things weren't adding up. Turned out my new LM3900 were bad. Between my two tubes, there was two different manufacturers of LM3900's.....three chips from one manufacturer....all the rest, another. Well, three chips turned out to be good :)

And I'll second......Do not use an "LS" series TTL in place of a "S" series TTL.

Edward
 
Wow... that smacks of remarked chips from China... I purposefully AVOID buying chips from there because of that.

If you still had them, I'd ask you to look at the tops and bottoms of the chips along with the shapes of the pins to see if they were marked the same but physically different parts.

Some chips have different mold mark locations and different shaped pins. If you had that yet they all had the same date codes and other info on top of the chip then odds are they are remarked chips.

A member of the neo-geo.com forums bought a couple of CXK-5814-35 chips from a supplier in China. No shock that they didn't work.
 
Why do you say that? For IC's I've had nothing but good experiences.

Three words:
"ESD, What's that?"

Eons ago, when I bought parts for myself at random places such as this -- I bought some 4000 series parts from Unicorn. They were shipped loose in a box with white peanuts (most static generating). Needless to say, half of them were dead.
 
You know things are getting bad if they are remarking chips that are less than a buck.
I didnt realize you were looking for "S". I might have those too, just inventoried a bunch of 74XX, 74S, 74F, 74ALS and none of its listed on my site yet.
I will take a look and see if I have it.
 
Three words:
"ESD, What's that?"

Eons ago, when I bought parts for myself at random places such as this -- I bought some 4000 series parts from Unicorn. They were shipped loose in a box with white peanuts (most static generating). Needless to say, half of them were dead.

Maybe they learned their lesson. All IC's i get are in the tubes. (ESD tubes that is :))
 
Maybe they learned their lesson. All IC's i get are in the tubes. (ESD tubes that is :))

Maybe they have improved. But, tubes are only antistatic and not static shielding. Big difference. Antistatic just means they won't generate static nor will they stop static. But if packed with white peanuts and not in a static shielding bag - then it's no different than being tossed in the box with peanuts.
 
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