hi everyone, I am making Schmitt trigger using LT1713 and it has two output and a latching. I don't know much about schmitt trigger using this kind of op amp. but not getting the expected signal. i want latching of 10us. and reference voltage is 60mv

 

Hi ashish,
Please post your LTS asc file.
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i want latching of 10us

What does that mean?

 

this is asc file

 

“latching of 10us” is confusing.
Do you want an output pulse of 10us?
If yes, you need a pulse generator such as a monostable multivibrator.

 

YEAH THE LATCHING SIMPLY MEANS WHEN OUTPUT IS HIGH ,OUTPUT REMAIN HIGH FOR 10US

 

hi ashish,
Is this basic simulation an indication of what you want, it needs a tweaking on the R/C feedback?
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I would use anyone of these: CD4098, CD4528, CD4528, 74LS123, 74HC123, 74HCT123.

 

This. What Mr Chips has suggested.

That is; If we are understanding the TS’s problem correctly.
Which I am afraid we are not. Because the behavioral description is that of a monostable, not a schmitt trigger.

 

I do not understand why the TS is trying to use a complementary op-amp as a pulse generator.
MC has it right in post #8 Use a device created and optimized for exactly that purpose. With most linear devices the characteristics needed for a stable pulse generator are not all defined in the data sheets, meaning no promise that they are controlled or constant from one device to the next.

 

I do not understand why the TS is trying to use a complementary op-amp as a pulse generator.

Hi Bill,
Have you noticed the amplitude of his 'trigger' signal which is a 100mV pulse of 5nSec and his Vref of 60mV

I would conclude it is the TS's intention by using this low level Comparator,
to avoid adding preamplifiers to raise these levels to logic for these devices CD 74LS 74HC , 74HCT

As I have posted before, read and understand the TS's requirement and intention.

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hi @ashish123456789

This LTS sim is a close approximation of your requirement.
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STARTING AT POST #1 i SAW no mention OF THE SIGNAL AMPLITUDE. I SAW THE REFERENCE WAS 60 MILLIVOLTS, but no description of the signal amplitude.

 

Hi Bill,
Marked up image, for 100mV pulse.
His text says for Vref= 60mV, but he set it for 600mV.
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In general, the standard process for seeking a solution to a problem is to state that problem in accurate detail. This is the standard approach of those folks seeking solutions that I have worked with in the past. It could begin with the statement I need to separate good parts from bad parts, and then usually provide some description of what variables needed to be measured and compared to a standard.
So the first step would be to tell us the goal, and then explain what would be the trigger.

"I need to generate a ten millisecond pulse when (this event) happens." would have been a great beginning.

So don't jump on me for missing something hidden in a simulation file that i can not open.