Quad comparator in a 14-SOIC — what the bench sees
The Texas Instruments LM339ADE4 packs four independent differential comparators into a single 14-SOIC package. Each comparator can sink up to 20 mA at the open-collector output, which also supports CMOS, MOS, or TTL logic levels depending on the pull-up rail. Supply flexibility is the headline here: single-supply operation from 2 V to 30 V, or split supplies from ±1 V to ±15 V.
Supply range and input offset — what actually matters for the BOM
The 0.25 µA max input bias current at 5 V keeps the error low when driving from high-impedance sources like a thermistor divider. Quiescent current maxes at 2.5 mA for all four comparators combined. That's about 0.6 mA per channel, which is reasonable for a general-purpose comparator in a non-battery-critical design.