LM339 Comparator

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LM339 Comparator

What is LM339 Comparator?

LM339 is a common integrated circuit that contains four independent voltage comparators inside, making it a quad differential comparator. It is mainly used in high-voltage digital logic gate circuits. LM339 can be easily used to form various voltage comparator circuits and oscillator circuits.

LM339 Pinout

The following figure is the LM339 pin diagram:

LM339 Pinout
LM339 Pinout

Pinout Description

Pin NumberSymbolFunction
1OUTPUT2Output 2
2OUTPUT1Output 1
3V+Positive Supply
4INPUT1-Inverting Input 1
5INPUT1+Non-inverting Input 1
6INPUT2-Inverting Input 2
7INPUT2+Non-inverting Input 2
8INPUT3-Inverting Input 3
9INPUT3+Non-inverting Input 3
10INPUT4-Inverting Input 4
11INPUT4+Non-inverting Input 4
13OUTPUT4Output 4
14OUTPUT3Output 3

LM339 Parameters

VIO±2 mV
IOS150 nA
ICC1.3 mA
IB250 nA
Common-Mode Range0V to Vcc-1.5V
Vcc2V to 36V (single-supply); ±1V to ±18V (dual-supply)
Vos5 mV
Number of Channels4
Min. Temp0 ℃
Max. Temp+70℃
PackageTSSOP-14, PDIP-14, SOIC-14

LM339 Circuit Diagram

LM339 Equivalent Circuit Diagram
LM339 Equivalent Circuit Diagram

How LM339 Comparator Works?

The operating principle of LM339 is similar to that of other comparator ICs, with each comparator having three pins, namely: inverting (-IN), non-inverting (+IN), and output.

To understand the working principle of LM339, let’s use one of its comparators as an example.

We take two input voltages, namely V1 and V2. Now, these voltages are compared using the comparator and the output is provided as Vo. Voltage V1 is connected to the non-inverting (+IN) input (pin 5) of the comparator, while voltage V2 is connected to the inverting (-IN) input (pin 4).

LM339 Schematic Diagram
LM339 Schematic Diagram

If the voltage at the inverting (-IN) input (V2) is greater than that at the non-inverting (+IN) input (V1), then the output will be logic low.

V2>V1, Vo = 0V or GND

If the voltage at the non-inverting (+IN) input (V1) is greater than that at the inverting (-IN) input (V2), then the output will be logic high.

V1>V2, Vo = VCC

LM339 Equivalent Models

LM311, LM324, LM397, LM139, LM239, LM2901, etc.

LM339 Application

  • Oscillator, Crystal controlled oscillator
  • Single-limit comparators, hysteresis comparators, dual-limit comparators
  • Voltage comparator, Negative Reference Comparator
  • Measuring instrument
  • High-voltage digital logic gate circuits
  • Rlectricity regulation
  • Logic Voltage Conversion
  • Measuring instrument
  • Driver CMOS, Driver TTL
  • Low Frequency Operational Amplifier
  • Sensor amplifier
  • Zero crossing detector


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About Author

Aidan Taylor
Aidan Taylor

I am Aidan Taylor and I have over 10 years of experience in the field of PCB Reverse Engineering, PCB design and IC Unlock.

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