comparator not comparing

[root2hell]

i dont understand why this comparator not going in saturation region, even i am using High speed comparator.

 

[jiripolivka]

i dont understand why this comparator not going in saturation region, even i am using High speed comparator.

I can see that your comparator does function, only the output amplitude is lower than expected.
Overshoots indicate something wrong with the DC power supply. I would suggest to add DC to ground blocking capacitors to the DC power supply, and check signal source impedances. You can reduce comparator gain by a feedback resistor like in an opamp circuit, sometimes it helps.

 

[THINKER_KAM_MAN]

I can see that your comparator does function, only the output amplitude is lower than expected.
Overshoots indicate something wrong with the DC power supply. I would suggest to add DC to ground blocking capacitors to the DC power supply, and check signal source impedances. You can reduce comparator gain by a feedback resistor like in an opamp circuit, sometimes it helps.

just a suggestion


reduce the pulse to 2V hight
the sine wave is 5VPK-PK it seems = 2.5v PK
therefore the PK value is all ways less than the pulse

 

[root2hell]

still not getting expected output...

and i dont know why i am getting inverted output.

 

[FvM]

There are both general and specicfic circuit faults involved

Generally, don't AC-couple a signal to an OP, comparator, transistor etc. without DC bias. In this case, simply omit the series capacitor.

Specifically, LM319 can't work without a pull-up resistor because the output is open collector type. Review the datasheet!

 

[godfreyl]

...i am using High speed comparator.

The LM319 needs a pull-up resistor at the outut. Try connecting the right side of R24 to +12V instead of ground.

edit - Oops, cross-post with FvM

 

[THINKER_KAM_MAN]

still not getting expected output...

and i dont know why i am getting inverted output.
View attachment 108559View attachment 108560

just a suggestion

what are you expecting?
the if the triangle is the o/p then its correct
the response time is the slew rate = triangle o/p

 

[Audioguru]

The output of this comparator and EVERY OTHER IC with an open collector output needs an output pullup resistor. A pullup is a resistor connected from its output to its positive supply voltage, not connected to ground as you have.
Then the output will be a squarewave and can be used for PWM.

 

[root2hell]

Thanks FvM. Today i get to learn what Open collector type output mean very basic but what can i do if i was not knowing that .

 

[Audioguru]

The datasheet for the comparator shows a pullup resistor at its output in every circuit that is shown.

 

[root2hell]

can anyone suggest me a fast integrator.

 

[Audioguru]

Why do you want an integrator?
If the comparator has a pullup output resistor then its output is PWM when it has the 50kHz sinewave and 500kHz triangle wave input signals in your first post.
An integrator is a lowpass filter which is slow. If you integrate the PWM output then you will have a signal the same as the 50kHz sinewave input.