It's basically a hobbyist's tool. If you wanted to make a simple circuit that would produce a "phaser" noise, it was great. If you were designing something that needed a stable oscillator you couldn't use a 555 because the oscillating frequency would vary tremendously with temperature. Same with the length of the pulse if you used it as a one-shot.
At the company I worked in the late '80s the frustrated management banned its use altogether after a series of failures in the field were traced to designs that relied on the 555 to be more stable than it really was.
If you were designing something that needed a stable oscillator you couldn't use a 555 because the oscillating frequency would vary tremendously with temperature. Same with the length of the pulse if you used it as a one-shot.
Those are all properties of the capacitors used, primarily, followed by Vcc stability. The 555 itself is a very long way down the list of Things That Make Oscillators Drift. Did you try polystyrene or polypropylene capacitors, or NPO ceramics? Supply pushing was also improved with the 7555 CMOS part, as I recall.
At the company I worked in the late '80s the frustrated management banned its use altogether after a series of failures in the field were traced to designs that relied on the 555 to be more stable than it really was.
>The 555 itself is a very long way down the list of Things That Make Oscillators Drift.
Well, this is true, but the chip put constraints on the types of circuits you ended up with.
>Did you try polystyrene or polypropylene capacitors, or NPO ceramics?
Eh, I don't recall, as this was 25 years ago. Probably. We were making one or two of each product, so the cost of the parts was a rounding error compared to development and test.
>Sounds enlightened.
They had been burned a few times in a sort of public way. Yeah, it was overkill. On the other hand by that time you could already buy phase locked loops on a chip, so there wasn't really a reason to keep using the 555 as an oscillator unless you were making something that had to use really cheap parts.
