Comment by gary_0
25 days ago
I would absolutely not want to use a microcontroller or a complicated chip for something like that. Simplicity is the point.
25 days ago
I would absolutely not want to use a microcontroller or a complicated chip for something like that. Simplicity is the point.
Supervisor chips are not complicated. In some ways simpler than a homebrew analog watchdog, and the good ones will handle failure modes a simple watchdog won't, like those that result in an oscillating output.
Yes, a simple purpose-made chip designed to be used in safety-critical situations, with high tolerances for voltage etc, would probably be better. Although one thing the 555 design has going for it is that a seasoned EE could take one look at the physical circuit and know exactly what it does.
But I would never trust anything that ran software for something like this.
It depends on the system's potential failure modes and what's required by your safety standard, not on one engineer's opinion of what's "best".