General-purpose quad comparator in 14-DIP
The Texas Instruments LM339N/PB is a general-purpose quad comparator — four independent voltage comparators in a single 14-pin DIP package. Each comparator compares two input voltages and provides a digital output that indicates which input is higher. The through-hole 14-DIP (0.300", 7.62mm) package is a legacy footprint, common in breadboard prototyping, through-hole PCB designs, and retrofit repairs on existing boards. It is not a surface-mount part — the board must have drilled holes for the leads.
The supply range spans 2V to 36V for single-supply operation, or ±1V to ±18V with dual rails. This wide compliance makes it usable across 5V logic systems, 12V automotive circuits, and 24V industrial control rails — as long as the ambient temperature stays within 0°C to 70°C. If your application sees freezing or high-heat factory floors, this temperature grade is a hard constraint.
Output type and drive capability
The open-collector output can interface with CMOS, DTL, ECL, MOS, or TTL logic families by pulling up to the appropriate supply rail. Input bias current is 0.25µA max at 5V, and input offset voltage is 5mV max at 30V. These are moderate precision specs — fine for threshold detection, zero-crossing detectors, and window comparators where a few millivolts of offset is acceptable. For high-precision sensing (sub-mV), a precision comparator would be a better fit.
Quiescent current and element count
Maximum quiescent current for all four comparators is 2.5mA. This is a single number for the whole package — each comparator draws roughly 0.6mA. In battery-powered designs, this is moderate; a micropower comparator would draw microamps per channel.