I have shown output image description here in my Lm 393 comparator, my output is not coming proper square wave.picture is shown below.i have described
my circuit. practically
I am using voltage comparator LM393 for comparing two signals, one signal is my reference signal which is a triangle wave, with voltages 2.08 volt generated by 555 timers above 200kHZ giving to the input terminal of inverting side of LM393 and input signal or modulating signal which voltage is less than 2.08 giving from function generator as a sinusoidal signal in the range of 1 Hz to 20kHz in the noninverting side of LM393. My question is when I am providing two signals it should be compared and give a square wave, but LM393 only taking triangle wave, sin wave is not going? why I don't understand. please give suggestion to the above points. In this picture below, I am referring to this circuit, please tell me what 's wrong in this circuit, when I am taking triangle wave from 555 timer ad providing into the comparator and another signal providing from the generator.
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\$\begingroup\$ One question per problem please, edit your question instead of creating new ones. Make sure you *thoroughly document" your questions so discussion is not needed to correct the questions. Thanks \$\endgroup\$– Voltage Spike ♦Commented Jun 29, 2020 at 22:52
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1 Answer
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Okay, so you appear to have a time constant of about 2 microseconds on the output.
If your pullup is actually 10K, that implies a capacitance of about 200pF, which seems a bit high even including your scope probe (use the x10 probe setting to minimize loading).
Check that the resistor is actually 10K and not, say, 100K.
Edit: It is very hard to read the pin names on your schematic. It appears you have COM connected to Vss but not grounded!
Also, this is not causing your problem, but you should not let the inputs float on the CMOS hex inverter.
answered Jun 28, 2020 at 15:11
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\$\begingroup\$ yes resistor is 10 k, and I have done the experiment using scope probe x10 \$\endgroup\$ Commented Jun 28, 2020 at 15:13
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\$\begingroup\$ in my circuit I have also put 0.1 if capacitor int non inverting end for decoupling dc also.what should I do? \$\endgroup\$ Commented Jun 28, 2020 at 15:15
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\$\begingroup\$ in my circuit, I am taking power supply from the lab bench dc supply which 3 ports,1-+voltage,2- negative voltage,3- COMMON , I am taking + V and -V. IS there is any wrong \$\endgroup\$ Commented Jun 28, 2020 at 15:26
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\$\begingroup\$ Are Pin 13 and Pin 2 on the (presumably) DIP IR2113 grounded or not? The schematic indicates they are not. \$\endgroup\$ Commented Jun 28, 2020 at 15:28
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\$\begingroup\$ Throughout the circuit, I am using TLC555 timer and LM393 comparator , on the output side I have only connected 10 k pull up resistor, I am not connected hex inverter till yet. \$\endgroup\$ Commented Jun 28, 2020 at 15:29