As I was designing a split voltage supply for an opamp supply, I thought that cutting one rail if the other rail wasn't at it's nominal voltage would be a good idea if I wanted a "good" output signal. Turns out it isn't that useful (at least in my particular case). BUT I'm still wondering how to do that. So for my curiosity:
How would one do that?
I have a split voltage (in my case it was +/-30 V and a load of about 25 mA. Although this post is hypothetical so not sure it's useful).
My idea was to use some comparator and the output would activate or deactivate a switch. Maybe a BJT or a MOSFET with a MOSFET driver. If I use a comparator like the LT1017, in it's datasheet the absolute maximum rating for the input voltage is -0.3 V to 40 V. So how can I monitor the negative rail with that? In one application example, V+ and V- are "switched". But can I use a negative Vref on INA- or INA+? And if it's the case, can the output of the negative rail comparator drive a switch (MOSFET or BJT)? Or MOSFET driver?