# VARYING Differential signals

Thread Starter

#### kashifMINHAS

Joined Dec 17, 2019
2
WHAT DOES IT MEAN BY (3~5)V Differential signal, and how I visualize it in single ended signal. How I adjust the gain of that signal to fixed level.

#### crutschow

Joined Mar 14, 2008
26,996
WHAT DOES IT MEAN BY (3~5)V Differential signal
What's the context for that statement?
Where did you read that?
How I adjust the gain of that signal to fixed level.
What do you mean "fixed level"?

Thread Starter

#### kashifMINHAS

Joined Dec 17, 2019
2
What's the context for that statement?
Where did you read that?
What do you mean "fixed level"?
1. (3~5) V means that a differential Analog signal whose amplitude is varying between 3 to 5 volts.
2. If this signal is put to Differential Amplifier whose output is single ended, then what is the amplitude of the output signal.
3. And how we fix the gain of that signal.

#### kubeek

Joined Sep 20, 2005
5,751
2. If this signal is put to Differential Amplifier whose output is single ended, then what is the amplitude of the output signal.
Depends on the gain of the differential amplifier.
3. And how we fix the gain of that signal.
No idea what you mean by fixing the gain. Making the gain fixed? Reparing uhm ..something?

#### TeeKay6

Joined Apr 20, 2019
572
1. (3~5) V means that a differential Analog signal whose amplitude is varying between 3 to 5 volts.
2. If this signal is put to Differential Amplifier whose output is single ended, then what is the amplitude of the output signal.
3. And how we fix the gain of that signal.
I believe that you are saying: If you apply a differential signal of 3 to 5 volts to the inputs of a differential amplifier that has a single-ended output, what will be the output voltage? The single-ended output voltage will be the differential input voltage times the gain of the amplifier. How the gain of the amplifier is adjusted depends on exactly what differential amplifier scheme you are using. If it's an instrumentation amplifier, tell us the model number. It it's an amplifier that you have built using one or more op-amps, then show us the schematic.

#### danadak

Joined Mar 10, 2018
4,057
Differential signal "normally" taken to be a signal that is not referenced to ground. A single ended output
generally refers to examining the signal between it and ground.

So take a R divider -

If you measure the signal across R2 then one leg is grounded, so this V at top of R2 is considered
in the "jargon" single ended.

However if you measure the V across R1 that is a differential V, and no matter what the Ground V is
its Vdifferential is only dependent on V1, R1, R2, and not Vground.

To maintain fixed signal level you need AGC circuit. One that compares incoming signal and
adjust either G of active AGC circuit,, or a V divider.

What frequency range of V are you trying to regulate ?

Regards,, Dana.