The lm392-N series consists of 2 independent building block circuits.
One is a high gain, internally frequency compensated operational amplifier, and the other is a precision voltage comparator.
Both the operational amplifier and the voltage comparator have been specifically designed to operate from a single power supply over a wide range of voltages.
Both circuits have input stages which will common-mode input down to ground when operating from a single power supply.
Operation from split power supplies is also possible and the low power supply current is independent of the magnitude of the supply voltage.