I need to detect when a signal rises above a threshold. The signal starts at ground. I want to use a LM311, with its -ve supply voltage at ground (to avoid having to generate a -ve supply) which means that the signal is sometimes below the specified minimum (but never below ground).
Can I assume that a LM311 will give the correct output provided the threshold on the other input is above the specified minimum, even though the signal is not?
Looking at the schematic for the LM311 suggests to me that this is OK, but are there any gotchas?
Sylvia.