Comparator output structure and supply flexibility
The LP311DR is a single differential comparator with both open-collector and open-emitter outputs — the open-collector pulls low against a pull-up to any rail up to 30 V, while the open-emitter sinks current from a negative supply or ground reference, giving the designer two level-shifting paths from one comparator.
Quiescent draw and input offset — the practical limits
Maximum quiescent current is 300 µA — low enough for battery-powered threshold detection but not the µA-class sleep current of a nanopower comparator; budget this into the system's always-on power budget. Input offset voltage is 7.5 mV max at ±15 V — for a 10 mV hysteresis window the comparator's own offset eats most of the margin, so plan a wider threshold or a lower-offset part if the trip point needs tighter than 15 mV accuracy. Maximum input bias current is 0.1 µA at ±15 V — negligible when driving from a 1 kΩ source (100 µV drop) but significant from a 1 MΩ source (100 mV drop); the bias current flows into the inputs and must be balanced with equal source impedance on both pins.