Questions tagged [differential]
Differential refers to any kind of signaling where the signal information is carried by two or more paths and both are required to properly reconstruct the signal. For example, USB D+ and D-
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How to calculate a differential + common mode LPF circuit?
I'm trying to validate my understanding of a differential + common mode LPF circuit using the AK4499EX datasheet (019001308-E-00 2022/07 version, p. 47). It presents the following circuit:
and its ...
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Display port eye diagram evaluation
I was testing my display port diagram, all 4 lines.
The first three look good, the 4th line looks like it has only one signal (not differential.)
My question:
Is the 4th line okey to be like this. (...
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Which is preferred over differential pairs: trombones or sawtooths?
I have been told that trombones are much better to use than sawtooths, even if sawtooths may be prefered in some certians scenarios.
Here I have added trombones to the differential pairs. If I had ...
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Distortion in a negative channel of the differential amplifier THS4505
I designed a single-ended to differential signal amplifier using a tool provided by Texas Instruments:
The source signal passes through a voltage follower (OPA810IDBVR), so the output resistance ...
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CAN bus accidentally swapped TX and RX is it possible to solve (in firmware) without board rework
I am interfacing an isolated can transceiver with my microcontroller. My schematic is given below.
Accidently TXD is connected to RXD of microcontroller and RXD is connected to TXD of the ...
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When compared to single-ended signals, do differential signals actually offer better EMI protection?
I'm looking for clarification on whether differential signals actually offer benefits with regards to EMI protection versus single-ended signals. Here is my current understanding (feel free to make ...
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Differential line driver built with discrete components
I need to establish an SPI communication over one meter in a very noisy environment. To do this, I am planning on using differential communication over a twisted pair cable.
I would use a dedicated IC ...
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What is the single line waveform of a resolver of sin or cos output?
For a resolver, the excitation signal is about 10kHz sin waveform. And the output are two pairs of differential ports: sin+/- and cos+/-.
If I test the output signal(such as sin+/-) by using a ...
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How to obtain differential measurements with an ADC
I have a digital scope and it has also differential inputs(+in_Scope and -in_Scope). I always obtain less noisy results using them comparing to and single ended wiring. Here below I draw what I mean:
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Question about differential signal routing [closed]
Would it be possible to know how we can calculate the distance that we must leave between two the two signals of a differential pair
And from what speed can we have crosstalk between the differential ...
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Layer stack up and impedance matching- 100 ohm
I have a 14 layer stack up as follows (the stack up is from EURO circuit):
I need to provide 100 Ohm differential impedance for my LVDS on layer 7, currently by the information from the manufacturer (...
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Ground in differential opamp situation
I have a setup like such in the provided schematic.
The idea is that I do have a -2.5 to 2.5V signal which I'd like to convert to a signal between 0 and 5V.
How should I connect my opamp? Should the ...
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How can I analyze HighSpeed traces what on Proteus project file?
I designed a few PCB on Proteus what includes High-Speed signal traces(USB, Displayport, GigaEthernet etc.). I want to analyze that High-Speed Traces. I expect see some values like eye diagrams, ...
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Impedance controlled PCB for USB 2.0?
We're doing a PCB for a customer that has Impedance controlled tracks for a microcontroller that seemingly might be max USB2.0, judging from lack of multiple data lines and the fact it goes in a micro-...
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Max voltage per pin when measuring differential voltage with MCP3422
Im measuring differential voltage over a 1 Ohm (shunt) resistor at max 1 Amp, load voltage is 12V DC using one of the channels on MCP3422. MCP3422 is powered from 3v3 DC.
The datasheet https://ww1....
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Altium Designer 24: directives on schematic, yet "No differential pairs in design" error when routing
I want to create an USB differential pair. I added the nets, name equally but changing P and N as the image shows:
SCH to PCB has been updated. Project comparator is enabled. No differential pair ...
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What happens if there is an impedance mismatch on differential pairs? [closed]
What do we encounter if the impedance changes along the way? For example, what kind of problem can we encounter when one of the two complementary PCB's is 90 ohm and the other is 100 ohm? For example, ...
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Simple example of first order ODE and Operational Amplifier
Hayt's (8th edition) Engineering Curcuit Analysis (Chapter 9, p360) contains an illustration of Operational Amplifier solving \$\frac{d^2v}{dt^2} = -9v\$. It is hard for me to understand how it was ...
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Virtex-7 FPGA Clock Constraint Configuration
I am moving from entry level FPGA such as Artix-7 (BASYS-3 board) to using a Virtex-7 (VC709 board). I have a question about how to setup the constraints file for the main clock of the Virtex-7 FPGA. ...
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Can I set LVDS permanently to HIGH or LOW with this simple circuit?
I have a chip with 14-bit LVDS input data lines (DATA0P/N to DATA13P/N) on the chip DAC3174. I don't have enough space left to route all these data lines, so I chose to set the two least-significant ...
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Dynamic circuit using second-order differential equation
For the past few weeks I have been trying to solve this dynamic circuit with no lock in solving the whole equation. I have difficulty in finding the contants at the end of the equation when coming up ...
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Are there fully differential feedback amplifiers with series inputs?
There are several examples of the 4 feedback topologies in single-ended circuits.
In the case of series inputs (i.e. series-shunt and series-series topologies), the input is connected directly to an ...
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Earphone audio level quiet and microphone not working
I am trying to connect wired earphones to a SIM800 GSM modem so the user can talk over phone calls. After a successful test with a terminal block and hand-soldered connectors, a PCB was designed. The ...
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How do I convert a differential RF signal to a single ended signal? [closed]
I'm using an RF transceiver that has a differential pair output. I want to route it to an SMA connector. How do I convert the differential signal to a single ended signal?
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Differential LPF cutout frequency simulation
While designing a thermocouple circuit, I saw that a 1 nF capacitor was placed at the differential signal input as shown in the figure. This was added for both differential signals, so I can see from ...
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Designing a differential amplifier
I was trying to design a differential amplifier in which the collector resistances of the transistors are 2.2 kΩ and are biased at 1 mA and are supplied with Vcc= +/-5 V . To find the Ro (the ...
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Confusion About Impedance Matching For Single-Ended and Differential Lines
I understand that for single ended RF signals I must ensure that the characteristic impedance of the transmission line matches the load impedance (say 50 ohm). I am a bit confused for differential RF ...
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Is a gap needed with LVDS with metal layer below it?
I have a 1.8 V, 350 MHz, 100 Ω LVDS signal on an FFC on the bottom plane. Below the FFC is an aluminum metal layer; the aluminum is pretty much unconnected from the FFC. The air gap/solder mask gap is ...
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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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Differential pairs / Single ended and the need for baluns
Excuse any blatant mistakes, I'm very clearly learning this new. Anyway from a purely transmission line perspective, it seems you can have a single ended line and a differential pair. I see the single ...
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M-LVDS differential signals through multiplexers
I'm experimenting with M-LVDS via USB 3.1 cables, passing the differential signals through the SuperSpeed lanes. I'm using the DS91M040 for driving M-LVDS. So far no issues, however, I need now to ...
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I would like to know what type of op-amp this circuit is
This circuit is connected to 250V AC power and I would like to calculate the values of the resistor and capacitor, but I don't know which formula to use to calculate it.
I think this circuit is ...
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Differentialy Fed Antenna Feeding Network
I need help with the feeding line for the following scenario. I have a dipole-like antenna for which I need balancing the input, see picture (dipole antenna used just for illustration; it does not ...
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Using Operation-Amplifier circuit to apply differential equation
$$ 6b(t)+\frac{8d}{dt}b(t)+\frac{10d^2}{dt^2}b(t)+\frac{4d^3}{dt^3}b(t)=12a(t) $$
I would like to implement this linear equation by using any type of op-amps. The solution will be the function b(t), ...
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Differential amplifier, calculation of differential and common gain
Maybe someone can help and knows how to calculate the differential gain and common-mode gain in a differential amplifier.
Will the formula for differential gain be Ad=Rc/2Re, i.e. in my case 50/40=1....
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Proof of half-circuit analysis of perfectly-balanced differential amplifiers
I have seen various approaches to the half-circuit analysis of perfectly-balanced differential amplifiers (see a particular example of a differential circuit at end if desired, but note that this ...
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Interfacing ratiometric sensor to precision differential ADC
Please consider following simplified schematic:
I'm currently in process of designing the analog interface for prototype heat pump driver/controller. It's job is to measure multiple analog inputs ...
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Why would a low-pass filter be connected to +5V on an RS422 differential line?
I am interested in a datasheet's schematic for my own PCB design of a similar system.
In my system, I am receiving an RS-422 differential line, and would simply be tempted to put a 100 Ohm terminating ...
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How to connect cable shield when receiver side powers signal source?
I have element 'A', the receiver, connected to earth, which powers modules 'B' and 'C', the signal sources, unconnected to earth. 'B' sends a differential line signal, and 'C' sends an analog signal. ...
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Why does the offset voltage have this polarity?
Consider the following from Chapter 3.5.6 of Analysis and Design of Analog Integrated Circuits by Gray, Hurst, Meyer, and Lewis:
As I ask about in a separate question, the authors claim that for some ...
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Why is an offset voltage and an offset current sufficient to represent mismatches in a differential amplifier?
Chapter 3.5.6 of Analysis and Design of Analog Integrated Circuits by Gray, Hurst, Meyer, and Lewis (GHLM) discusses the effect of device mismatches on the behavior of emitter- or source-coupled ...
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Low-Voltage Differential Signalling (LVDS) not working
I have updated the schematic and hopefully included all the suggestions.
The problem of the LED strip flickering is still there, however, I have noticed a slight improvement after altering the circuit ...
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How can I get a differential output as an input for another circuit on ADS?
I'm currently making a project on ADS for a differential pair oscilator:
The desired output for this circuit is Vout2-Vout1.Now, I want to plug a buffer on this circuit, but I don't know how to ...
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Is the voltage on the negative of a differential pair actually below the ground voltage used to generate the signals?
Apologies if it’s obvious but I always hear that differential pairs have a negative and positive waveform (one on each line) that’s opposite. Now I get that you could choose whatever value or point “...
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Low Side Bus One Shot
I'm confused on what exactly a one shot is and how to identify it on prints. For this example I know there is supposed to be a one shot on the low side of a 69 kV / 12 kV bus, but I'm not sure how ...
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Transmitting differential video signal to the ADC input
I'm designing a circuit that converts a single-ended analog video signal (f = 10 MHz) to a differential pair and then is processing the data to a digital form. The signal is transmitted through a ...
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What is the difference between PN- and PM- Differential pairs?
I am looking in the past recent weeks in a lot of datasheets and I see PM labels for LVDS (Low voltage differential signals) or generally Differential pairs on the Block Diagram. Altium would ask me ...
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Differential DAC filter capacitor options
The standard output filter for a DAC with a differential voltage output looks this way:
simulate this circuit – Schematic created using CircuitLab
However, some DACs have this filter ...
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Designing a single-ended to differential driver to DC2588A-A evaluation board
I'd like to test the DC2588A-A, and I noticed that the user guide mentions it's driven by a pair of ADA4899-1 DRIVER amplifiers. However, the user guide doesn't provide clear information about the ...
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Understanding the purpose of REFT and REFB on a differential ADC
I am using the Analog Devices AD9238 ADC for a project and I am confused about the purpose of the differential voltage references (REFT and REFB).
I am powering the AD9238 from a +3.0V supply and I ...