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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differential instrumentation amplifier in LTspice not working
I was trying to simulate an instrumentaion amplifier in ltspice.
the problem i am having is the output when measured across C1 is wrong. since i have an amplification factor of 11, i was expecting to ...
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1answer
48 views
No gain in CMOS differential amplifier
Currently I'm working on the design of 1st stage of CMOS differential amp (pic. 1). I'm using classical design to achieve at least some gain. I'm using CMOS 90nm process and SPECTRE simulator.
So far ...
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1answer
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Simulating PMOS differential amplifier in Cadence
I am studying about rail-to-rail opamp design and I am trying to recreate the Itail vs Vgs (in this case input common voltage) curve from the link bellow (pages 5 and 6):
https://mixsignal.files....
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Improve range on a differential ADC
I'm using an MCP3425 ADC, it has differential inputs but I'm using it as single ended mode.
The signal that I want to digitize comes from an integrator circuit (an op amp with a capacitor in its ...
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20 views
Attenuation in the circuitry of differential vs isolated probes
Using this website as a reference for differential probes:
https://circuitcellar.com/research-design-hub/high-voltage-differential-probe/
By Andrew Levido, Circuit Cellar
The differential probe is ...
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0answers
38 views
Differential communication, VCC and GND recovery
modern MCUs are consuming so little power that I started thinking about using only two differential data transmission lines for sending not only data but power also. I made a simple schematic below of ...
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1answer
37 views
What could be causing differential signal drift?
I looking at a differential signal on a scope, and I see that while the signal should be exactly equal and opposite the values are slowly drifting slightly.
The quantity I'm looking at is the areas of ...
2
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1answer
42 views
I2C differential network architecture using PCA9615
I'm building an architecture for a large scale robot (3x3meters) and I would like to build a specific architecture around I2C differential to control motors drivers (this should be noisy).
My problem ...
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1answer
37 views
Measuring voltage without a common ground
When measuring a power source voltage using a differential amplifier, without a common ground with amplifier supply, to which ground should we connect the differential amplifier resistor ground? V1 ...
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1answer
30 views
Maximising sensitivity of AC voltage measurement on top of DC voltage with Arduino ADC
I have:
Single supply rail voltage (3.3)
current sensing transformer that outputs an 1v pk-pk value at is max rated sensing current (10A). The Transformer biased at 1v DC in order to ensure that the ...
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2answers
77 views
Read USB data to arduino [closed]
If I take a USB cable connect it with my cellphone from 1 half and in the other end I connect VCC and GND to VCC and GND pins of the arduino and the D+ and D- pins to digital pins and use a ...
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1answer
34 views
Differential signalling with negative feedback
Does differential signalling always comes hand to hand with a negative feedback circuit?Else the 1s and 0s would be the same!because if we have ground in the inverting pin then the output voltage will ...
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Is a fully differential opamp subtractor possible?
I know how to subtract two single-ended voltages with an opamp configured as a subtractor.
I'm learning about fully differential signal processing and I'm wondering if it is possible to subtract two ...
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1answer
68 views
Equation for RC circuit
I have the following circuit
I have solved the equation this far:
I have solved the equation this far $$ I_C + I_{R1}=I , U=I_{R1}R_1 \implies I_{R1}=\frac{U}{R_1}, Q=CV \implies I_C=C\frac{dU}{dt}, \...
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1answer
48 views
Textbook confusion with CMRR and transconductance mismatch
I am just looking for an explanation on how a 2% mismatch in aspect ratio (W/L) results in a 1% error in transconductance paramater g_m (I can't figure out latex right now). The textbook conveniently ...
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2answers
370 views
Differential probe design ground copper pour
What is the reason of no copper pour at the differential input side of the board. What would happen if i pour ground copper at that area as well.
The source of the design
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Voltage Subtractor this circuit:
Is this a voltage subtractor switching the position of Q1 with Rc1 and Q2 with Rc2 ?Also if we want current to flow from the + sign to the - sign how many times bigger resistor than Rc2 and Rc1 do we ...
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How does this branched electrode circuit work?
How does this circuit yields the output below?
(Source: Guerrero FN, Spinelli EM, Haberman MA. Analysis and Simple Circuit Design of Double Differential EMG Active Electrode. IEEE Trans Biomed ...
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1answer
37 views
Multiple differential tranceivers on single bus
Im using a few moduls of rs422 tranceivers connected on single bus
Easy module has transciver with TX input, RX output power end differential pair output and input - but no EN pin to hold the ...
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1answer
34 views
signal types and wire types
I am trying to understand the selection criterion for choosing between a signal types and wire type out of the following:
Signal types:
Gnd reference uni-polar signal
Gnd reference bi-polar signal
...
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0answers
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What could be the reason if the AC coupling option goes away when I attach a differential probe (P6248) to a Tek MSO5204 scope?
When the scope is not attached, I could see both AC coupling and DC coupling options for the channel settings. The moment I attach the differential probe, the AC coupling option goes away. Any reason?...
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1answer
72 views
Solving a simple single-ended differential amplifier
simulate this circuit – Schematic created using CircuitLab
N.B. I_D=KVov^2 without the 2
Iām really confused with this excercise, my problem is to calculate the A_v=v_out/vd and the cutting ...
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1answer
115 views
Locally hatched ground plane to increase differential impedance
I am designing a flexible PCB to carry two types of differential signals. One is about 1.2Gbps 100R differential impedance, while the other is only 3Mbps, with much more tolerance on the impedance.
...
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2answers
51 views
Converting differential-current output to single-ended voltage; adjustable gain
I want to convert differential-current output of DAC2902 to single-ended voltage. Can I do it with following differential op-amp configuration at the output of the DAC?
The voltage gain is fixed = 1 ...
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2answers
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Is this slide wrong about the differential signal waveform?
While learning about the differential signals I saw this youtube video. It looks like this slide does not correctly shows the voltage levels of the complementary differential signals, as I have marked ...
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1answer
383 views
How to do low pass filtering on a differential signal
If I have a differential signal on a pair of wires then how would I do a simple RC low pass filter on this differential signal?
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1answer
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What to do with GND of differential mode signals?
Let us say I have 2 modules. First module gives a differential signal output on a pair of wires while the second module takes the differential signal input.
When I connect the differential signal ...
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1answer
64 views
Open-loop frequency response for an op-amp
I want to know what is the ideal circuit to measure open-loop frequency response and why?I have seen the typical open-loop frequency response curve for an op-amp a lot of times. But when I try to plot ...
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1answer
45 views
Use of twisted pairs with fundamentally single-ended DUT
Let's suppose I'm interested in measuring the voltage response of a DUT to some imposed voltages. The DUT takes V1, V2, V3 as inputs relative to some GND, and outputs V4 relative to the same GND. All ...
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2answers
87 views
Is it possible to route USB 2.0 using regular traces?
In the future I will be faced to design a system that includes USB 2.0 connectivity. I've seen that there are many trace calculators, but as far as I can see, they refer to microstrip lines.
So, is it ...
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0answers
51 views
Degenerated Differential Pair voltage headroom
I was reading about ways to make the differential gain linear by adding degenerative resistors Rs as shown, but it has voltage swing limitations, having swing reduced by Is*Rs( when one of the MOS ...
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3answers
95 views
Wiring a BJT differential amplifier in a circuit
I need to switch a 12V relay when an input signal passes a certain voltage threshold. I use this popular BJT amplifier:
In my case:
VCC = 5V
...
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1answer
51 views
Is this signal reflection or a damaged transmitter?
This is (an isolated, differential) capture, 1Āµs/div, of some Profibus communication over about 10m of cable. The first image is typical for about 90% of packets and seem fine. Most are +/-5v with ...
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Texas Instruments fully differential op amp app note: I'm having difficulty understanding an equation (single ended to differential video conversion)
I am developing a circuit to convert single-ended video to differential, based around the TI article "Converting single-ended video to differential video in single-supply systems" by Jim ...
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0answers
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Long tailed pair not working to compare signals from 2 LDRs
I've been trying to compare my signals from 2 LDRs to feed into Arduino's ADC.
However I can not get any gain from my differential amplification.
The problem comes when I have high resistance from 1 ...
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1answer
49 views
CAN Split Termination Capacitor Calculation
I'm trying to use the split termination on a CAN bus, but I'm a bit confused about the calculation for the split termination capacitor. It is described in Figure 10 in the Texas Instruments app note ...
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0answers
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ADC negative input clipping vs scaling and bias
So, I have this differential ADC (AD7641) and plan to use AD8139 as his driver. The goal is to digitize a signal (a sine wave) of about 3.5Vpp and 36KHz. The signal is actually single-ended and ...
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1answer
56 views
Long tailed pair
How do I adapt the long tailed pair to fit my requirements?
I've seen circuits where they use 9V Vcc with 10k resistors.
From my understanding the resistors are there to prevent floating base from ...
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2answers
65 views
Difference between two gain +1 op-amp topologies
I've got two differential driver circuit designs that take a single ended input and provide as output a buffered pair of +1 and -1 times the input and I'm struggling to understand the difference ...
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1answer
56 views
How to take my differential filter and design it for a different frequency and impedance?
I have a board with this differential PI filter:
simulate this circuit – Schematic created using CircuitLab
Say it's designed to pass signals with frequency X and bandwidth B1, and now I want ...
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2answers
139 views
Differential amplifier input voltage higher than the supply voltage
I want to measure current at high side of circuit but input voltage is higher than the op amp supply, is it ok to do the input voltage division like schematic below?
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0answers
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“Coupling” gain-setting resistors in a single-ended source, differential amplifier?
I am working on a fully differential amplifier design that receives a single-ended differential voltage from a piezo sensor.
I computed a theoretical gain and selected appropriate resistors and it ...
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1answer
288 views
How do industrial PSUs switch to 4-wire measurement?
Almost all high end PSUs provide a 4-wire voltage measurement at the load, How do they switch to 4-wire measurement?
Is it in software, reading another ADC channel or they use a relay? Can it be done ...
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1answer
38 views
Can a differential probe and regular coax wire be connected safely to only one channel of scope using a tee connector?
I would like to ask if I can connect a differential probe and a coax wire through a tee connector to 1 channel of an oscilloscope, in order to take different DC measurements.
The connection topology ...
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0answers
40 views
Solve differential equation for R-L circuit
Given that Ri+Ldi/dt=Vsin(wt).
The answer given here is
i= (V/Z)[sin(wt- Ī¦) + ke^(-t/Ļ)].
I could not solve this equation further.
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Flipped length and Z-matched lines. How to pcb patch?
I think the title says it all. I accidentally flipped the P and N lines downstream of a CSI/MIPI retimer (they are impedance and length matched). Is there any way at all to patch this on the pcb?
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Single ended biopotential amplifier
I have to design a single ended biopotential amplifier circuit based on an already existing model for differential amplifier.
In other words, I have a circuit in which each channel has two inputs from ...
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1answer
64 views
Confusion on operation of bipolar differential amp (long tailed pair)
Let's say there's a basic differential amp constructed with two npn BJTs.
And a current source is working as the tail.
The task I have is to amplify a small AC signal of around 1mV p-p, referenced to ...
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0answers
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Difference Amplifier to retrieve sine wave
I have built the following summing amplifier circuit from a Fourier approximation of x(t)= 0.143 + 4/Ļ ā((sinā”(2Ļ(2k-1)ft)/(2k-1)). I am now trying to retrieve a sine wave from the output of the ...
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3answers
126 views
op amps comparator or differential amplifier
I have a part of electronic schematic as described bellow, I'm a little bit confusing about the function of the LM321 amplifier. In this case, can we say that is a differential amplifier or just a ...
