LM339 quad comparator (DIP-14)
LM339 · four comparators · 2–36 V single supply · open-collector outputs (each needs a pull-up) · sinks 16 mA
Try it on the benchThe lab drops it on an empty bench and opens its datasheet card.
Pins
- OUT 2
- OUT 1
- VCC
- IN1−
- IN1+
- IN2−
- IN2+
- IN3−
- IN3+
- IN4−
- IN4+
- GND
- OUT 4
- OUT 3
Ratings and limits
| Supply | 2–36 V |
|---|---|
| Outputs | open collector, sink 16 mA |
| Response | 1.3 µs |
How to use it
Four comparators in one package: battery level bars, window detectors. Each output needs a pull-up resistor.
Lessons and builds that use it
- 18650 battery level indicator (build)
- 12 V low-voltage battery cutoff (build)
- 9. Comparator: a clean decision at dusk (build)
- 10. Relay: switching a real lamp (build)
- 11. PIR sensor: only when someone is there (build)
- 12. 555 timer: stay on after they pass (build)
- 13. Buzzer: an alarm mode (build)
- 14. Solar: the light runs off-grid (build)
- Single 18650 charger with a 3-LED charge indicator (green 80–100 %, yellow 40–79 %, red below 40 %) (build)