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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Confusion with two types of differential signal coupling
I'm having difficulty to articulate the question. But perhaps I might get close to it by an example.
I know that in differential signaling, both the signal and the receiving amplifier can be in ...
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Common-mode choke in ECG circuit
I'm designing a PCB for single lead ECG measurement and I ran across this TI reference design that contains a common-mode choke (P/N Murata DLW31SN900SQ2L). What's strange is that I can't find any ...
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Why are common mode chokes used in Ethernet magnetics
I’m trying to understand the reason the common mode choke is required in Ethernet magnetics. To understand, if we look at the schematic, with the common mode choke (horizontal coils) removed, we are ...
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Current sense GND planes Power & Signal
I couldn't find a clear answer anywhere.
I have a battery powered device which therefore has a VBAT+ and a VBAT-.
The battery is used through some power stages (which contain MOSFETs which are driven ...
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Common mode and differential mode filters order
In power supplies input filters the common mode block (typically a common mode choke) is usually placed first, and then the differential mode block follows. The image shows this structure.
Is there ...
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Current Rating in Common Mode Choke
What is the meaning of this current rating which says "unbalanced" current?
I know in common mode chokes the common mode current rating is given. Why here it is written as Iunbal.?
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How are SPICE files created compared to S4P files generated from a VNA?
When measuring impedance versus frequency using the same data in both SPICE and S4P formats, why do I obtain different results?
COMMON MODE IMPEDANCE
Common mode impedance 10514 Ohm at 79.1 MHz
S4P ...
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Why is the core resistance modeled as 2*Rp and capacitance as Cp/2 in a common-mode choke?
I directed my attention to a paper regarding the modeling of common-mode chokes. Within this paper, the authors structured the circuit in such a manner that they designated the core resistance (...
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How is the boundary of input CM level calculated?
I will briefly state my understanding of the following equation, and then pose three questions at the end.
Equation (1) (2) refers to the circuit in the first picture, Equation (3)(4)(5) refers to the ...
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Why will the offset of a source-follower which is connected to the output of an opamp as a voltage buffer limit the op-amp output swing?
I am currently reading chapter 12, "The Common-mode Feedback Circuit" in Analysis and Design of Analog Integrated Circuits by Gray and Hurst.
Page 815, gives the following statement for ...
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Testing input common-mode voltage range of an op-amp
I have been trying to develop a set-up that could test the input voltage range and output swing of an op-amp.
To measure the input voltage range, the output should swing within the limitations ...
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CM filter of differential input(AD7383-4)
I'm trying to make a 3-phase inverter using AD7383-4 for converting analog current signal to digital.
Typical application of AD7383 which is given by datasheet. AD7383 gets pseudo-differential input ...
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How to write \$V_{\text{a0}}\$, \$V_{\text{ab}}\$ and \$V_{\text{cm}}\$ for the three-phase three-level inverter in terms of the switching signals?
How to write \$V_{\text{a0}}\$, \$V_{\text{ab}}\$ and \$V_{\text{cm}}\$ for the three-phase three-level inverter in terms of the switching signals?
For the three-phase two-level inverter, the values ...
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Common mode voltage with configurations of Opamp
I am reading this article (https://www.analog.com/media/en/training-seminars/design-handbooks/designers-guide-instrument-amps-complete.pdf) in order to understand more how traditional instrumentation ...
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Add common mode noise into existing circuit
I have a complex 24 VDC in circuit that I need to demonstrate fault cases as a result of potential common mode noise due to a floating earth on the PCB. As such, I am interested in the best way to ...
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