LM393 voltage comparator and its typical circuit introduction

I've been watching some open source projects these days , Many codes have no comments , Tired of reading ！

Look at the chip ！！

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LM393

Main uses ： limiter 、 Pulse generator 、 Square wave generator 、 Time delay generator 、 Digital logic gate circuit 、 Multi frequency oscillator and so on

Pin distribution diagram

Equivalent circuit diagram

When the voltage at the same phase terminal is greater than the voltage at the reverse terminal , Output high level ; When the voltage at the same phase terminal is less than the voltage at the reverse terminal , Output low level ;

Typical application circuits are available for reference in general data instruction manuals .

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LM393 modular

There are many SCM switch modules through LM393 To make the .

for example ： Light switch , Vibration switch 、 Hall sensor 、 Photodiode switch 、 Flame sensor switch 、 Infrared obstacle avoidance module

LM393 modular

Allied LM393 The modules are the same , Don't talk about circuits , That is, the boards are the same ！！

The slight difference is that there are four lines ( Pictured above ) And three wire . The difference is that an analog quantity detection port is introduced , One kind doesn't lead out .

The circuit principle diagram

When the brightness of the light is below the threshold ,D0 Output high level ; When the brightness of the light is greater than the threshold ,D0 Output low level .

The realization function of other switches is to replace the photosensitive resistor in the figure above with related components , Then you can adjust the adjustable resistance ！！

This is the simplest comparator circuit .

Back D0 Directly connect the triode to directly control the relay ！ No programming yet ！ Programming is just a few lines , It belongs to simple application .

 

although LM393 and LM358 Same in electrical symbols , But don't swap easily .

LM393 It's a dual voltage comparator ,LM358 It's a dual operational amplifier

LM393 Working in nonlinear region , It can be regarded as an operational amplifier with very large magnification

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LM393 Schematic diagram

When the voltage at the same phase terminal is greater than the voltage at the reverse terminal , Output high level ; When the voltage at the same phase terminal is less than the voltage at the reverse terminal , Output low level ;

The circuit structure of in-phase input terminal and inverse input terminal is the same ！ To avoid errors belongs to .

The circuit diagram is relatively simple , Analysis should be able to see how to achieve ！

If the rooster has to lay eggs —— The work that should not be done must be done

LM393 This is a voltage comparator , If you want him to work as an operational amplifier , Need to introduce feedback resistance .

It's not that you can't make an operational amplifier , Even the official manual lists several applications of amplifiers .

for example ：

Each Handbook has relevant applications .

however , I suggest ！ Just use its comparator function ！！

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OK, Today I only saw the usage of one chip , Be lazy 、 It's been a rotten day , Hope to make persistent efforts in the future ！