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Author Topic: Differential amplifier  (Read 1204 times)

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Offline arh8080Topic starter

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Differential amplifier
« on: May 16, 2016, 05:26:55 am »

Hi this circuit how it works?Please help me

Excuse Friends
How Output Can Change Value From 500mv to 1200mv?
My English is not so good Excuse me.
« Last Edit: May 17, 2016, 04:15:42 am by arh8080 »
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Offline Marco

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Re: Differential amplifier
« Reply #1 on: May 16, 2016, 08:27:27 am »
Your image upload server is not responding.
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Offline danadak

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Re: Differential amplifier
« Reply #2 on: May 16, 2016, 02:10:19 pm »
Looks like an integrator to me. R5, C1 set time constant. And DAC
used to bias up the OpAmp, for what specific reason (using a DAC)
I do not know.

R2 and R3 also a part of biasing inputs (inverting).
Vbias = 3.6 * ( 10K / (10K + 18K ) ) =~ 1.3V

Maybe the DAC is used to handle the errors in R2 and R3.


Regards, Dana.
« Last Edit: May 16, 2016, 02:19:17 pm by danadak »
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Offline Marco

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Re: Differential amplifier
« Reply #3 on: May 16, 2016, 03:16:56 pm »
No DC feedback path ... something screwy going on.
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Offline danadak

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Re: Differential amplifier
« Reply #4 on: May 16, 2016, 04:43:30 pm »
Good point Marco, that circuit will eventually stop functioning
due to accumulated charge on C's.

And input range not R-R. ~ 1V off the positive rail.

Regards, Dana.
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