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SN74LS322AN substitute

lucasdaytona

lucasdaytona

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Jul 23, 2011
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Hello, I have a dead SN74LS322AN IC here (from a XT clone motherboard, legs became rusty, then broke), and I'm having trouble in finding another identical chip, I looked some datasheets, but I could not decide what IC would work. Could any of you guys point to me if it is possible to use another IC?

Thanks!
 
Are you having trouble locating the part, i.e. 322, or the family, 74LS ? (Or what other parts are you looking at )
Edit: Actually, I found some 74LS322 currently on eBay.
patscc
 
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I suspect that the ALS322 part is much rarer than the LS part. Given its application, you could probably get away with a 74HCT322 or even 74S322. Forget the suffix--that's mostly revision and packaging. If it's in a DIP you can probably use it just fine.
 
I was speaking in general sorry, the 322 only has a LS version that i can find in my books even.(They are outdated though)

There seems to be a HC version too but those you cannot use because they are not TTL compatible.
 
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Pick up some 20-pin sockets, or header-type sockets, while you're at it, if you don't have any. It's a sin to replace an IC and not use a socket if at all possible.
patscc
 
patscc said:
It's a sin to replace an IC and not use a socket if at all possible.
patscc
Click to expand...
Generally Accepted Practice and I often do it myself, but why???

Sockets are an extra expense, a common point of failure (some more than others), and they stand out like a sore thumb as not original.
 
No CLPD no FPGA only standard logic 74's and 4000's and microcontrollers.(and 805's and other standard components)

it has to do with global availability and lifetime.
 
Crypticalcode0 said:
No CLPD no FPGA only standard logic 74's and 4000's and microcontrollers.(and 805's and other standard components)

it has to do with global availability and lifetime.
Click to expand...

Good grief, at the rate that new microcontrollers are coming out, I wouldn't expect them to have any greater lifetime than a 30-year old CPLD.
 
Crypticalcode0 said:
No CLPD no FPGA only standard logic 74's and 4000's and microcontrollers.(and 805's and other standard components)

it has to do with global availability and lifetime.
Click to expand...

Hi
I have nothing against programmable logic and it certainly has its place. However anyone who has had to do long term support for long obsolete electronics can certainly relate to either getting the PLD equations in the technical data or just using common non-programmable parts as just common sense.

"Simple" PALs can and are a major PITA once the original developer goes out of business and the equations are lost. There are several S-100 board designs that are effectively lost to history due to this problem. There is no source of repair for PALs once the equations are gone. Trying to reverse engineer them is difficult and expensive except for a few trivial cases.

Thanks and have a nice day!

Andrew Lynch
 
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