Questions tagged [common-mode]
A common mode signal is a signal that is common (i.e. has the same magnitude and phase) to both inputs of an electrical device, as opposed to a differential mode signal. It is often desirable to reject common mode signals, in which case the common mode rejection ratio (CMRR) is an important metric.
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Differential amplifier common-mode gain
How do you find the common-mode gain of this circuit. Lambda > 0, and gmro >> 1. Using Av=-GmRout
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What is the relationship between attenuation and impedance with these common mode chokes (CMC)?
I have a question regarding 2 CMCs. We want to filter some common mode noise from 150 kHz to roughly 700 kHz. Trying to resolve some AC mains conducted emissions measurements.
The two CMC we ordered ...
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Input common mode for a switched capacitor integrator
I had a question about finding the input common mode of a differential switched capacitor integrator (shown in the figure below).
The integrator is a conventional delaying integrator with two non-...
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Signal Integrity Course - Differential Mode vs Common Mode - What is the diagram stating?
I'm currently taking an informative video course titled "PCB Signal Integrity" by Douglas Brooks.
I've attached a screenshot below where the instructor presents a diagram illustrating the ...
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Understanding differential buses: characteristic line impedance
Lately, I've been studying filters and differential buses, and there's still one detail that doesn't fully make sense to me — it's related to the line impedance and how it may affect the calculations.
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Doubt in a Differential Amplifier Chapter's Example
I was revising the differential amplifiers chapter and come across this example. I just wanted to confirm a thing, Let me know if that is correct:
1.) In Figure a, the Vout+ is only getting the ...
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Why does ATM90E32AS require GND connection despite differential inputs?
I’m working on a test setup using the ATM90E32AS energy metering IC. As an analog signal source, I’m using an AD9833 waveform generator connected to an Arduino. I generate a 50 Hz sine wave from the ...
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Instrumentation Amplifier Circuit simulation not yielding expected results
I want to measure the voltage across a rheostat located in a remote and noisy environment. The rheostat is far from the main circuit, and its cable runs alongside many high-current-carrying cables. ...
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Why does an op-amp's common-mode input voltage range not shrink with higher open-loop gain?
I'm trying to understand the relationship between an op-amp’s open-loop gain and its input common-mode voltage range.
Let’s say I’m working with an op-amp that has a power supply of 2V and an open-...
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Input common mode voltage spec of an opamp
In the datasheet snapshot below we can see the 'input common mode voltage' specified for a certain op-amp. (Datasheet-THP210)
Here is a application circuit of the same op-amp taken from the same ...
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Transfer Function of multiple feedback bandpass filter (with Vcm at positive terminal)
How to calc bpf 1 transfer function? all questions I see on net have gnd at non-inv term. but here it is Vcm because of which constant term coming. how to get Vo/Vi?
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How is this circuit with feedback stable when the phase margin seems to be negative?
I am working with a driven right leg circuit, whose purpose is to attenuate the common-mode voltage \$V_{cm}\$ on the body by sensing the common-mode voltage, amplifying it (and reversing polarity), ...
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Do cascaded common mode chokes add to each other?
Will cascaded common mode chokes give an impedance which is the sum of their individual impedances over their respective frequency ranges? By this, I mean if we graphed the CM impedance of multiple CM ...
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20 Vrms 60 Hz Test Signal
I'm looking to generate a 20 Vrms 60 Hz test signal for the CMRR test of IEC 60601-2-27.
I haven't been able to identify a waveform generator beefy enough to output 20 Vrms. Would there be ...
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Significance of common mode voltage in a chain of differential ICs [closed]
When interfacing two differential ICs (lets call them IC#1 and IC#2), does the common mode output voltage of one IC#1 needs to match common mode input voltage of IC#2?
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