555 Timer Circuits

In some respects, it's a testament to how much the world of electronics has changed over the past ~25 years. It used to be that 555 was this Swiss-army-knife IC that you had to learn about. Multiple people published entire books about it!

Today, it's essentially obsolete. You're quite unlikely to find it in any competently-done commercial designs. Every analog trick you can do with it can be done more cheaply, more reliably, with better power efficiency, and with fewer external components using a modern MCU.

It's not that analog is dead, but it's solving different problems now. Including how to keep ultra-high-speed digital signals usable within the footprint of a PCB - which wasn't that much of a consideration in the golden days of the 555.

There is still at least one niche for it: very simple circuits which requires >5v. Using 555 lets you skip the regulator and drivers.

But even there, it's high Iq limits its applicability.

I'd guess that a 555 is also tougher than a microcontroller. I'm putting together an HV supply and thought about using a microcontroller but opted for a 555-based oscillator. Either one won't survive HV but I think the 555 will handle stray charges better.

Modern mucus are surprisingly fault tolerant. Just saying. It’s not like the bad old days where if you sneezed at a cmos chip it would probably be fried. I’m not sure how that stacks up to a 555 though.

My mucus is about as fault tolerant as it ever has been. Sometimes it gets really thick if the weather is dry or I'm sick, but otherwise I haven't noticed any difference. I find that drinking water helps.