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LM339 Datasheet, LM339 Comparator, Circuit Schematic, Pinouts and Sources

LM339 Datasheet PDF and LM339 Comparator Circuit Overview

LM339 comparator is a low power, low offset volatage quad comparator.  These devices consist of four independent voltage comparators that are designed to operate from a single power supply over a wide range of voltages. Operation from dual supplies also is possible, as long as the difference between the two supplies is 2 V to 36 V, and VCC is at least

LM339 PDF, Comparator Datasheet LM339 Comparator Pinout

LM339 Price Check

LM339 Comparator Technical Description

The LM339 comparator series consists of four independent precision voltage comparators with an offset voltage specification as low as 2 mV max for all four comparators. These were designed specifically to operate from a single power supply over a wide range of voltages. Operation from split power supplies is also possible and the low power supply current drain is independent of the magnitude of the power supply voltage. The LM339 comparators also have a unique characteristic in that the input common-mode voltage range includes ground, even though operated from a single power supply voltage.
Application areas include limit comparators, simple analog to digital converters; pulse, squarewave and time delay generators; wide range VCO; MOS clock timers; multivibrators and high voltage digital logic gates. The LM339 comparator series was designed to directly interface with TTL and CMOS. When operated from both plus and minus power supplies, they will directly interface with MOS logic- where the low power drain of the LM339 comparator is a distinct advantage over standard comparators.

LM339 Comparator Circuit Schematic

LM339 Comparator Circuit Schematic


LM339 Comparator Pinouts

lm339 Comparator Pinout


LM339 Comparator Project: VU Meter

LM339 Comparator VU Meter

The circuit uses two lm339 voltage comparators to illuminate a series of 8 LEDs indicating volume level. Each of the 8 comparators is biased at increasing voltages set by the voltage divider so that the lower right LED comes on first when the input is about 400 millivolts or about 22 milliwatts peak in an 8 ohm system. The divider voltages are set so that each LED represents about twice the power level as the one before so the scale extends from 22 milliwatts to about 2.5 watts when all LEDs are lit. The sensitivity can be decreased with the input control to read higher levels. I have not built or tested this circuit, so please let me know if you have problems getting it working. The power levels should be as follows:

  • 1 LED = 22mW
  • 2 LEDs = 42mW
  • 3 LEDs = 90mW
  • 4 LEDs = 175mW
  • 5 LEDs = 320mW
  • 6 LEDs = 650mW
  • 7 LEDs = 1.2 Watts
  • 8 LEDs = 2.5 watts