How do you properly monitor supply voltages for digital circuits (microcontrollers, FPGAs, RAM)? (I stumbled upon this question when working on safety critical systems)
What I have seen a lot is to have ADCs which measure the supply voltage regularly, but these kinds of circuits perform weakly against glitches as most of the time the ADC is not measuring at the right moment. Glitches can lead to memory corruption, which can be catastrophic. Furthermore, having a look at http://www.analog.com/media/en/technical-documentation/product-selector-card/Supervisorsfd.pdf it seems like some resilience against detecting glitches seems even desired. What makes sense, because as long as a glitch does not have a certain width or depth, it has no impact.
But I have also stumbled across some ICs (an RTC for example) which besides their normal brown-out circuitry have some edge detection to detect sudden rises or falls on the supply voltage.
To summarise, isn't it desirable to have beside the normal "static" voltage monitoring (with things like ADCs or comparators) some circuitry which can detect glitches (of a big enough width of depth to have an impact)?