Yes: Show us your schematic with all the voltages and inputs.
Usually you can rely on the circuits given in the datasheets. So - sorry for this - I assume there is an issue in your circuit.
Klaus
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I underlined "your", because with many threads here the people say "I used the circuit like given in the datasheet", but when we finally see the true circuit ... there are differences (by accident or not).
I second Klaus' request.
Include all actual component values. Mention what supply voltages are being used.
If you include voltage readings and/or waveforms at some key test points, that would also help.
If the schematic has been followed, I would guess the problem is a lack of voltage at the output pull-up resistor.
The point labeled "VLOGIC" is a voltage input and should be tied to the supply of the logic gate following the circuit. If you do not provide that voltage, the circuit will still work but be unable to produce any output signal.
Ok I am attaching the image of my circuit drawn in proteus. It does not work there as well.
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Ok I am attaching the image of my circuit drawn in proteus. It does not work there as well. . oops I Also included 2.2K resistor from pin 7 and diode in reverse mode.
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Please ignore previous postings. See the attached image. Sorry for the inconvenience.
Now we have the same informations as in the datasheet.
To see what works and what not we need to see the output signals.
At least all the output signals of U1 and U2.
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Btw: You said the "real circuit" is not working. And it is no breadboard. Therefore I assume you have a PCB.
Do you have a schematic from your PCB tool? Because this schematic seems to be a Proteus schematic.
Or did you use Proteus to route the PCB.
In any case: the PCB layout could provide additional informations..
In post#2 I tried to explain, that we don´t need any schematic. Not this from the datasheet, not this from proteues.
It is very likely they are correct, therefore they are about useless for finding the issue.
What we need is the schematic of the circuit that does not work.
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If you made a PCB you should have the related schematic. Please post that schematic.
Kindly understand that I constructed schematic based on breadboard connection. If I show breadboard screen shot, it will be impossible to make out anything. If you have same circuit working in your lab, please share it. I have checked about everything, including rewiring half a dozen times. Fig.14 works just straight (stand alone V/F, without hiccups).
You have to divide and conquer a circuit. You already know that the LM311 is working. Now test the opamp integrator on its own, and check out its proper operation
I find it impossible that an integrator circuit's output remains exactly at zero, even in an absence of an input.
The opamp's own offset voltage would make the output to crawl towards saturation unless it is periodically reset.