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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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 discusses the effect of device mismatches on the behavior of emitter- or source-coupled differential ...
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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 ...
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Ethernet MLT-3 signall probing
I am getting radiated emission failure in my system, where the emissions were out of limit (~5 dB) for frequencies 125 MHz, 175 MHz, 225 MHz, 275 MHz, 775 MHz, 825 MHz. This sounds like the odd ...
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USB to FTDI connection
I try to connect USB 2.0 to a FTDI FT2232HL. This is my first high speed layout.
I am planning to use 2-layer board 1.6 mm. I know that I have to keep 50 Ω Z0 and 90 Ω Zdiff. However with the 2-layer ...
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Difference between current and voltage expressions in fully differential circuits
In the fully differential circuit below, the common-mode (CM) and differential-mode (DM) voltages are defined as
$$V_{DM} = V_1 - V_2$$
$$V_{CM} = \frac{V_1 + V_2}{2}.$$
Considering the CM and DM ...
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Differential Amplifier with unbalanced differential signal
The circuit topology of figure 1a corresponds to a differential amplifier with resistor load.
Since the signal generator available in lab does not have a differential output, a balanced
differential ...
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TRS differential input and output connector wiring for balanced audio CODEC I/O connections
I've been studying the ADAU1361 evaluation board and noticed an odd thing how the differential input and output connectors are connected in their schematic on its user guide, page 7, focus on the left ...
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How to calculate the via fence spacing between two differential CPWG?
I designed a very compact 4 layer PCB that has many PCIe 2.0 differential pairs spaced in close proximity. In addition to the internal ground planes, I want to fill the signal layers with copper, and ...
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What are the most effective techniques for reducing the negative effects on differential pairs routed on top of two different ground planes?
I have an FMC Card with analog circuitry containing channels. I've separated the ground for these analog channels into two distinct planes: AGND and PGND.
PGND serves as the ground for the power ...
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USB (low speed) on stripboard: can it work?
I recently designed a PCB, with a connector for an extension module for "future uses" (with various signals: GPIOs, I2C, SPI, USB2.0, USB3.1, PCIe Gen4).
The connectors are fine pitched (and ...
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How do you wire up the PCA9600 I2C bus extender to use differential signalling at 12V?
I would like to use a 12V differential signal between two NXP PCA9600 I2C buffers to extend I2C at 100kHz to about 15m over 100-ohm twisted pair (CAT6). My original understanding from a brief look at ...
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Is the output of this DC-DC converter considered a differential pair?
Very new to electronics.
I am using this DC-DC converter in one of my designs. It is a dual output (+/- 15V) DC-DC converter. I have read a few articles about how important it is to keep differential ...
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Connecting LVDS to oscilloscope using ferrite bead to isolate GND/SHIELD
I want to measure LVDS signals with a scope.
Will my solution work? (Shown at bottom.)
I know of other ways of doing this, but I am hoping this way is cleaner and easier.
Specs:
Frequency:~100MHz
...
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Mitigating 2.4GHz interference from 0-5V analog signaling line
I am chasing my tail on a project and cannot seem to find a way out of the hole.
I have a small 18mm 40kHz piezo transducer running through a powered precision rectifier+preamp circuit. This tiny ...
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MUX for different voltage levels
I have a project which has two inputs. Based on what signal the user inputs, a MUX (or something else (not relay - it needs to me ultra small and very low power)) directs it to the appropriate pins of ...
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Time-Varying Inductance in Electrical Systems
How to derive and solve equations for electrical systems when the inductance of an inductor is not constant and changes over time?
I'm familiar with the standard equations like E = 1/2Li^2 or V = Ldi/...
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Over voltage protection for 5v differential line
I am working on a stepper motor driver that will use 48V as a power source, this driver will have encoder interface. The encoder has 3 differential lines which will only tolerate 5V.
I want to protect ...
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CSI differential pairs differential impedance : follow Jetson design guide or standard 100R value?
I'm designing a PCB based on the Jetson Orin NX system on module, using a camera (MIPI CSI PHY-D).
The problem is that the design guide of the Jetson is giving me a differential impedance of 90-...
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How to plug phase and neutral on this differential? [closed]
I have replaced an old differential with this one:
Since there's no indication how/where to plug in line and neutral, can you please help?
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Finding transfer function in a balance state
I have an ODE that looks like this:
$$
\dfrac{d^2y(t)}{dt^2} + 2\sin{y(t)} = u(t)
$$
Taking u as input and y as output, considering the balance state with
$$
u(t) = \bar{u}, y(t) = \bar{y}
$$
...
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Highlighting Differential Pairs in Altium
The PCB was designed, the gerbers were extracted in rs274x format. But it doesn't include the rs274-x2 version (so doesn't include differential pair impedance information). What can I do to highlight ...
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Are the supply voltage and differential signals put on the same connector?
I have a circular connector. Assembly card size coming from the mechanical department limits me so I must use the pins of the same circular connector for 28V DC power supply and some differential ...
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HCSL source vs. end termination
Regarding HCSL I wonder why there is source termination at all?
If in case of source termination, at receiver side there is no termination or a high impedance input, then the input reflects nearly all ...
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'Best' topology to measure this weird sensor standard
I am developing an embedded solution to measure and record the analog signal from a PCB Piezotronics pressure sensor. Specifically the Model 124A21.
The sensor has some integrated circuitry to boost ...
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Weird pinout of USB ESD protection
The USB ESD protection component USBLC6-2SC6 seems to be very popular (?). However, its pinout seems not ideal:
The USB differential pair should be routed close to each other, but the pinout of ...
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PCIe Gen4: inter-pair skew: any limits?
For PCIe (and more particularly PCIe Gen 4), is there any recommendation on the maximum inter-pair skew, i.e. the maximum time/length difference between either:
2 TX differential pairs (of different ...
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What is a voltage-controlled differential current source & how do you simulate it in simulink?
I am trying to achieve the same circuits designed in this paper:
https://arxiv.org/abs/1512.05064
by simulating it in simulink, yet I can't seem to understand what it is referring to by saying voltage-...
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Differential pairs without ground plane
I need to make a small PCB, this PCB is just for switching from one connector to another, it's just an adapter to change the pinout of the connector. So, there are no components, but only traces.
The ...
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SX1261/2 transceiver design: Antenna pins and balun
I am designing my first transceiver (first PCB/IC that uses an antenna). I chose SX1261/2 because it is cheap and supports LoRa protocol. While designing the PCB and reading the datasheet of the IC I ...
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The MIL-STD1553 transceiver IC has differential pairs with the same pin names. Should I connect them?
The MIL-STD1553 transceiver IC has differential pairs with the same pins . Should I connect them?The IC that i use holtic hi 2130 and I couldn't see any warning in datasheet about it. In the ...
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Interface Ethernet voltage
I just want to know what are the voltage levels on the Ethernet differential lines (both single ended voltage level wrto ground & different voltage between the pairs). I haven't measured the ...
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Path of common mode noise in a DC-DC converter
I have a doubt about the common mode noise propagation in DC-DC converters.
Consider a simple Buck converter,
the switching nose is where the potential difference between the varying voltage occurs ...
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Differential op amp feedback resistors
I understand if you do not have negative feedback in any op amp configuration then the output will be unstable (will oscillate for example) and the feedback resistor and input resistor on the negative ...
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Zigzag pattern on differential traces
Does anyone know what this pattern means in Altium Designer? If it is related to a warning, how do I get rid of it?
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Benefits of a differential PA in an RF power combiner design
Looking at the schematic for the Shure PA770 Antenna Combiner (found in their FCC listing) we can see the design is fairly straightforward, some amplification before combining via a typical Wilkinson ...
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10/100 Ethernet Routing Review
I know it is a big favor to ask, but this is my first ethernet design, so could you provide input on the routing from connector to mag and from mag to PHY? Is it fine or how can I improve it?
Really ...
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Using a differential op amp to convert a differential pair into a single ended signal
I need to convert a differential pair into a single ended signal and would like to use a differential amplifier to do this.
Using the above circuit and the ADA4850 I was hoping to achieve this but of ...
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AC Source RC Circuit Differential Equation
I have to find the differential equation to this circuit and I have been stuck for two days. I have tried: KCL in loop 1 and loop 2 but I don't know how to do the current through the inductor as Vi(t) ...
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Questions regarding ESD protection
I have a couple of questions regarding the Basics of ESD.
Usually, when we employ ESD protection, say placing a TVS diode on the signal line, the other end of the ESD diode terminal:
a) Will be ...
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