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Quad differential comparator

LM339 Basic Circuit

Build a basic LM339 circuit with labeled pins, component values and connection guidance.

Package view

LM339 in a circuit

A 2 V reference, a pull-up and all unused inputs defined.

5Vsupply3,GND12.15kand10kdividerVREF2Vtopin6;VINpin7;OUT1pin1pullup10kto5Vandlogicinput. Unusedplus5,9,11GND;minus4,8,10VREF;unusedoutputsopen.
VIN above VREF releases output1; its 10 kΩ pull-up then makes a HIGH.

Connect it, step by step

Follow the component values and pin connections

Create a reference

The resistor divider makes 2.0 V nominal from 5 V.

Add the output pull-up

Read the output with a high-impedance logic input or meter.

Define unused inputs

Bias unused channels away from equality and leave their outputs open.

Component view