IC Replacements

[Gil]

Will the following chips be good as replacements :

Original IC       Replacement IC

SN74LS75N      SN74HC75N
HD14011BP      CD4011BE
HD14051BP      MC14051BCP

Is the first two letters refering to the manufacturer
(so I can basically refer only to the 14xxx and the suffix when searching for a replacement ?)

[pjwhite]

Will the following chips be good as replacements :

Original IC       Replacement IC

SN74LS75N      SN74HC75N
HD14011BP      CD4011BE
HD14051BP      MC14051BCP

Is the first two letters refering to the manufacturer
(so I can basically refer only to the 14xxx and the suffix when searching for a replacement ?)

Those should all be OK, maybe with the exception of the 74HC75 as a replacement for a 74LS75.  You will need to check the voltage levels driving the inputs and make sure they meet the specs valid logic levels for HC logic.   (Refer to the data sheet).  You may need to add pullup resistors on the inputs of the 74HC75 if whatever is driving them doesn't meet the specs.  Output current may also be an issue if the 74LS75 is driving LEDs or other high current circuits.

And, yes, the first two letters generally indicate the manufacturer.  SN is usually Texas Instruments, I'm not sure about the HD -- it's probably Harris or Hitachi, MC is Motorola and CD is a common prefix used by many manufacturers for CMOS logic.

[Gil]

How about the suffix of the SN74LS75N (=>75N)

Should it be the same in the replacement as well ?

I got the following ICs here - are they OK as replacement for SN74LS75N ?

SN74LS32N
SN74LS02N
DM74LS08N

Thanks !!

[niftydog]

sometimes the replacement will work perfectly, other times it won't work at all. It often depends on the circuit itself and how the chip is used. The designer may have relied on a specific parameter of the original chip in their design, and any variation could cause incorrect operation.

as for the prefixes and suffixes, it's a real grey area. Different manufacturers attach different definitions to different suffixes. The only way to be 100% sure is to obtain the manufacturers datasheet, but that is often not possible.

LS is low power TTL (read; less current source/sink and slower than most other familys of logic ICs)

HC is middle of the range CMOS and is compatible with TTL logic levels.

You should be ok.  :? But, as it depends on many factors there are no guarantees.

How about the suffix of the SN74LS75N (=>75N)

which manufacturer?

You should be able to determine the maker by locating and deciphering the logo on the chip. Then you've got some hope of finding the meaning of the suffix by searching their web site.

I got the following ICs here - are they OK as replacement for SN74LS75N ?

SN74LS32N
SN74LS02N
DM74LS08N

absolutely not. They are entirely different devices.