Comparator (4 input) LM339

The Comparator (4 input) LM339 is a quad voltage comparator IC: it contains four independent comparators in one 14-pin package, each with its own pair of inputs and an output. Each comparator checks which of two voltages is higher and switches its output accordingly, which makes the LM339 a simple way to turn analog sensor signals into clean on/off signals for logic circuits and microcontrollers.

LM339 Comparator (4 input) Specifications

• Function: 4 independent voltage comparators
• Supply voltage: 2 V to 36 V single supply, or ±1 V to ±18 V dual supply
• Supply current: about 0.8 mA
• Input common-mode range: includes ground
• Outputs: open collector, need a pull-up resistor; work with TTL, CMOS and microcontroller inputs
• Response time: about 1.3 µs
• Pin count: 14

Comparator (4 input) LM339 Applications

• Light, dark and temperature threshold detectors
• Battery low-voltage alarms
• Window comparators and level indicators
• Zero-crossing detectors and square-wave oscillators
• Line-following robot sensor boards

What's in the Box

• 1 × LM339 quad comparator IC

Tip: Because the outputs are open collector, add a pull-up resistor (for example 10 kΩ) from each output you use to your logic supply. If the output chatters on slowly changing signals, add a little hysteresis with a high-value resistor from the output back to the non-inverting input.

Orders placed before 14:00 are ready for pickup the same day. Delivery across Lebanon usually takes 1–3 working days.