So a fake may not be as precise/not work as well?
virtuos1:
So a fake may not be as precise/not work as well?
Really it is a crap shoot. Fake or counterfeit you have no clue as to the origins and manufacture. Not just with things like a ten cent 555 timer but higher end things like processors. The only way to make sure you are not getting a fake or counterfeit is buy from a reputable source. The picture on Ebay or similar means nothing because what you see may not be what you get.
No, fake or counterfeit may not and likely won't work as well. Take a NE555 Read the data sheet including all the specifications. Will the hundred chips for $5 USD meet all those specs? Would you trust your life and limb to them?
This is not complicated.
Ron
Critical industry including aviation, automotive and medical (among others) have strict requirements and chain of control to ensure this doesn't happen... and if it does to go after the folks that allowed this to happen.
...but if you're just blinking an LED and want to save a few bucks with 555 of questionable origin, have at it. I have several hundred 555 used to build a little test station that work fine. They have tested fine... in fact they might even be made for Ti or others but was branded generic so they don't have issues... but its a crap shoot. 99.9% of chips I source from China are fine. The ones you need to be careful about are the ones that are loosely packaged... they might have been picked up from the reject pile and sold to unsuspecting folks. All manufacturers have chips that don't conform that get thrown out.
It's also interesting that sometimes the fakes work better than the original... but won't work with the original because they fixed mistakes... lol.
Got it.
Just wash them with soup and then dry and use
daniel_85:
Just wash them with soup and then dry and use
Cock-a-leekie works best.
I've worked with 555's in an industrial application and after that experience, I wouldn't even trust my life to a major branded, major distributor supplied part.
555's are a poor chip to choose for any professional application, as the CMOS equivalents like the 7555 are
much better behaved to the supply. The original 555 pulls spikes of 100 to 200mA from the supply when
it switches, requiring heavy decoupling and generating noise.
Don't get me wrong the 555 is an iconic chip, I just substitute 7555 for it.
MarkT:
555's are a poor chip to choose for any professional application, as the CMOS equivalents like the 7555 are
much better behaved to the supply. The original 555 pulls spikes of 100 to 200mA from the supply when
it switches, requiring heavy decoupling and generating noise.Don't get me wrong the 555 is an iconic chip, I just substitute 7555 for it.
Yeah but CMOS chips are very sensitive to static electricity so if you use it for something important (like medical or something) and then it gets zapped...
Not once it is built into the equipment. 
Hmm no CMOS for critical? I better let the automotive, medical, military....etc guys know stop using that stuff.
Hey better stop using mosfets too while we’re at it
That having been said, I have never been particularly careful around CMOS. I tend not to bother with earthing straps etc and have not ever had a failure, so they are not as vulnerable as some make out.
Once in a properly designed circuit I would trust CMOS chips much more these little microprocessors. They are tougher and tolerant to much higher voltages. They just work.