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 can i Implement this circuit in practice? Vcm and source signal addition
I am just wondering that how this circled path would be implemented on a PCB. Previous stage is just an opamp based amplifier(Inverting amp.)
Vcm is provided by the ADC in the last stage but I have no ...
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31 views
Design of Fully Differential OTA Circuits
This is the equivalent model of an ideal single-ended OTA:
Now, this is the equivalent model of an ideal fully differential OTA:
Now, is there a rule for getting a certain circuit with a fully ...
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52 views
Replacement 100 ohm resistor for differential scope probe? [closed]
I'm trying to use a P7504 ($$$) "TriMode" scope probe, and unfortunately the resistors eventually break. Does anyone have recommendations for a 100ohm resistor that would replace the ones on the probe?...
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41 views
Differential input circuit design frequency issue?
The current design for this differential op amp scales down -/+ 10V 100kHz signal inputs to 0-3.3V for an ADC to properly read. Using a gain of .165, it adjusts -10 to 0 by adding a 1.65V offset, as ...
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55 views
Terminating Resistors on Ethernet Port
I'm using Ethernet (CAT5/5e/6) cables to communicate with the PCA9615 Differential I2C buffer. These cables roughly have a characteristic impedance of 100 ohms, but I have a few questions about ...
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Best method to drive SPI over 1 m
In my current project I need to control 8 analog multiplier. They are controlled with SPI but without the MISO line, so I would need to route :
SCK
MOSI
8 slaves selects
So 10 signals in total. The ...
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30 views
How to control microphone-speaker connection between two SIM800Ls with a GPIO terminal?
There is a device consisting of two SimCom SIM800L quad-band GSM/GPRS modules and controlled by an MCU, presumably ESP8266. The idea is to let the first SIM800L call one person, the second SIM800L ...
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33 views
MOS working point in a differential analog mixer
let's consider this simple configuration of a balanced differential mixer (analog multiplier):
I have understood that the local oscillator is generally a high signal, while the radio-frequency signal ...
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72 views
Negative voltage on both inverting and non-ínverting inputs of a differential amplifier gives non-zero output
I used an LM324 op-amp for my differential amplifier, in which the inverting input voltage is constant and the non-inverting voltage varies between the range -1.30 V to 1.30 V.
I am having an issue ...
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42 views
Can I directly connect microphone to speaker of two SIM800Ls
There are two SimCom SIM800L quad-band GSM/GPRS modules. I would like to make some kind of call relay, such that SIM #1 accepts incoming call, then SIM #2 executes outgoing call, and once both ...
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38 views
What type of MUX to most effectively connect both sets of resistors at once?
The following circuit is used PER CHANNEL, and I have 4 channels, to according scale the gain for our input signals on each channel.
However, each channel, has to be able to switch between 4 ...
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44 views
Doubts about a differential negative resistance oscillator
let's consider this kind of differential negative resistance oscillator:
The output of this circuit is VA - VB. My book says the following sentence:
From a quick analysis of the circuit it can be ...
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50 views
BJT Differential amplifier. Tail Resistance. Input Resistance
Here is the schematic of the BJT diff amplifier, I wanted to solve (design). The task is from the book "Art of Electronics".
Exercise 2.18. Verify that these expressions are correct. Then design
...
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67 views
How can I find i1 and i2 in function of Vg in this circuit?
Given the attached schema I'd love to find the analytical temporal and frequency expressions for the current in the 2 branches: i1 and i2.
R0, R1, R2, C1, C2 and Vg(t) are given. In the time domain ...
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274 views
Swapping out RJ-45 connector on Differential I2C circuit
I'm trying to use Sparkfun's Differential I2C Breakout circuit into my own design, and I'm looking to replace the RJ-45 connector. It's too big (having a footprint size of 15.24 mm x 15.24 mm), and I ...
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372 views
How do we explain the common-mode feedback in an intuitive way?
There are such beautiful circuit ideas that make you hold your breath and admire them silently. Such an idea is the common-mode feedback (CMFB) in fully differential amplifiers. I was not familiar ...
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Is it OK to have flying leads on a differential pair?
I'm designing a small daughterboard that contains a microcontroller and a USB port. This board also has a connector to allow it to connect to a motherboard.
What I'd like to be able to do is to have ...
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71 views
LM324 output voltage gets low in difference amplifier configuration when UPS supply is turned on
I am using lm324 as difference amplifier to measure the string voltages of lithium ion battery pack ( four cells in series). I am using all single package of LM324 that have 4 Op-amp.
The Lithium ion ...
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2answers
66 views
How to make sense of the signal trace of differential signal
I am trying to understand following signal trace picture that is shown on the wiki page of 1553 Bus. The Bus has balanced differential pair wires.
As the 1553 bus has differential signals on the ...
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3answers
125 views
Differential Pairs and GND
I have some doubts about different configurations of differential pair I have seen in many cases:
In these schemes, biasing network for the gate is not shown for simplicity. All of them are excited ...
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58 views
Gain of single input differential amplifier
When performing the small signal analysis of the circuit shown below, with \$ V_{1} = V_{in} \$ and \$ V_{2} = 0 \$, and output taken from \$ V_{02}\$, I consider the small signal model for half of ...
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Impedance Control in Twisted Pairs and PCB
Why do differential signal traces on a PCB require a reference plane to have a controlled impedance?
Whereas, in an unshielded twisted pair there is no reference, there are only the two conductors?
...
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87 views
How does a CAN transceiver work?
CAN Transceiver Transmit Mode
I try to understand the transmit functionality of a CAN transceiver. I found this post a good starting point, but it doesn't completely answer my question.
Block ...
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Response of a Differential Pair to Differential Mode Signals
I do not understand this kind of analysis of a Mosfet Differential Pair:
This analysis wants to prove that, when a purely differential mode signal is applied (so opposite signals are applied between ...
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1answer
28 views
Connect GND/signal-output-pins to differential-input-pins
I have a device outputting a signal (-10V...+10V) referring to GND. Now I want to feed this signal into another device, that only accepts differential inputs (-10V...+10V).
Is it possible to just ...
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Parabolic wave equation, electric and magnetic field definitions
The split step solution for Parabolic Wave Equation (PWE) applied to the tropospheric propagation problem is:
$$u(x+\Delta x, z)=e^{ikM(z)10^{-6}\Delta x}\mathfrak{F}^{-1}[e^{\frac{-ip^2\Delta x}{2k}}...
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1answer
89 views
Differential Pair Length Matching
I am routing a 16 bit ADC chip, the LTC2217 (datasheet) to FPGA. Each bit is an LVDS pair and I know +/- of the pair should be the same length but what about from pair to pair? I have 2 of these chips,...
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1answer
31 views
Input and Output Impedances of Single to Differential mode converter
I have this circuit that converts a single ended input signal to differential output signal. I want to understand how to calculate or find out its input and output impedances?
The two op-amps are in ...
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36 views
Help in analysing circuit to show which resistor controls the differential gain
I understand the circuit to be a summing circuit but I am struggling to analyse past this point: Vout = R5 (((-R2/R1 * V2)/R4) * (V1 / R3)). can anyone analyse this further to prove that R5 is the ...
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2answers
63 views
Op amp output voltage swing vs noise
Staying within an op amp's specified output voltage range, how does a difference in output swing affect the op amp's noise applied to the output signal? Obviously by increasing gain, we amplify the op ...
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1answer
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wiring Tamura 4 pin hall effect current transducer to differential daq
How do i wire a 4 pin hall sensor:
200A model below
https://www.mouser.com/datasheet/2/397/L03SXXXD15-469349.pdf
I don't understand the wiring schematic below
I currently have +15 to pin 1, -15 to ...
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54 views
Using common mode choke in differential configuration for differential mode EMI filtering
Why is it not popular using common mode chokes in differential mode configuration for differential mode noise filtering?
Mostly when using fly-wire type chokes with filters, where the chokes are ...
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43 views
Input and Output Impedances of Differential Amplifier
I have this circuit that is used to convert an incoming analog differential input signal to a single ended signal. The differential input is connected at IN+, IN- and the output is taken from OUT.
I ...
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1answer
60 views
How is the differential mode noise suppressed by adding a capacitor across the Lines
I was reading about the common mode noise and differential mode noise.
I don't understand how a differential mode noise gets coupled and how adding a capacitor across the line will help.
I ...
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1answer
56 views
Common mode and differential mode noises
I want to understand common mode and differential mode noise more intuitively.
I have read this article. But I would like some analogy or experience with real circuits with some example to understand ...
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52 views
How can I implement a differential input for a logic analyzer probe?
I'm currently working on a project to build a portable logic analyzer. There will be 4 input channels to the design, however I was highly recommended to redesign this using a differential input to ...
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97 views
Why measuring a differential signal requires a differential probe?
I am planning to measure an RS485 signal with an oscilloscope. Since I want to see the signal that is "seen" by the receiver side, I was planning to plug the reference terminal of probe to Sig(-), and ...
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Stepping Down Logic Level of a Differential Signal
simulate this circuit – Schematic created using CircuitLab
Suppose I have a unipolar, differential 24V signal, and I want to step it down for use with a 5V differential receiver (such as RS-422)...
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Differential Pair with non-differential inputs
consider the following
In normal circumstances, Vin1 and Vin2 change differentially, if Vin1 goes up by 10mV, Vin2 goes down by 10mV. Makes sense.
But I'm wondering, what would happen if Vin1 went ...
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146 views
Long-tailed pair - gain and bandwidth
I'm trying to understand this schematic of this differential probe:
I marked some blocks. I have some questions about the block I marked "Long-tailed pair" (LTP). I have no experience with LTPs so ...
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3answers
150 views
Differential filters: high pass, low pass, band pass
I am looking to use a band pass filter in an EMG circuit design using the differential signals you receive from an op amp (differential/instrumentation). I have been looking for what is the proper way ...
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1answer
41 views
How to obtain a high precision mV signal within a specific interval using a variable resistor?
I want to design a circuit which outputs a signal ranging from 0-70 mV using a variable resistor ranging from 80.51 Ohm - 183.05 Ohm and a supply voltage of 12 V. My idea so far has been to make a ...
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Differential to single ended digital signal
i have a 8GHz differential clock to convert to single ended. Is taking one end of the clock enough? what are the risks of doing so?
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1answer
129 views
Differential low pass filter to single ended -> Differential low pass filter
I'm designing an audio DAC based on the PCM1690 from TI. Datasheet
One requirement of the DAC is differential outputs. Since the PCM1690 has differential outputs, this is not a problem. However, the ...
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54 views
Single-ended analog signal to differential
I need to transmit 2 analog signals over a cable in a noisy environment.
How to transmit them as differential ?
Given that :
Each signal can be used to inject and receive current (< 130 kHz, &...
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43 views
EAGLE. Differential pair routing. Width of the track changes after first change of direction
I try to route differential pair of tracks. When I click the mouse to change the direction it also changes the width
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1answer
116 views
How to transmit analog signals over cable?
In my current project, I need to transmit 4 analog signals (A1, A2, A3 and A4) on a cable from one PCB to another. I am working at 3 VDC and the distance between them is relatively short (< 30 cm).
...
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139 views
RS485 Eye diagram - does it look good?
I got a new diff probe, I am trying it out on RS485. I'm triggering on the rising edge. The RS485 is running at 25Mhz.
Does the eye diagram look good?
Could I double the speed (50MHz) and be ok? (...
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45 views
Quadrax routing on a PCB
When connecting twisted pair wires to a printed circuit board, I hope I am right in thinking that differential pair routing is used on the board in either a stripline or a microstrip configuration to ...
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1answer
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Capacitor across Vlo and Vhi on DAQ, switching power supply
I have a switching power supply (RC Esc). I am measuring the input voltage from battery using a voltage divider. The Divider is attached to a differential DAQ. I have very large transient spikes ...
