Questions tagged [dc-offset]
The dc-offset tag has no usage guidance.
122
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How to trim offset of a folded cascode op-amp when different voltage in applied to the input portion?
When the common mode input voltage is varied, offset is also varied. How can I trim them without using any pot?
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113
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Generate a sine wave with MCU
I want to generate a sine wave without an offset voltage. I generated a sine wave from 0 to 3.3 V and it has a 1.65 V offset. I need a sine wave from -1.65 V to 1.65 V using an MCU. How can I do that?
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DC offset cancellation
I am working on THz detector and was going through research papers.
In the receiver stage a preamplifier is used in the circuit shown below.
Why can't we directly use the amplifier?
How does the dummy ...
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Is there a better way to digitally phase-control this triac?
This is a follow-up to a previous question which has a more detailed background of the problem I'm trying to solve.
I've built a wireless remote controller for a model train I have that runs on ~18VAC ...
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How can I produce AC with a DC offset, isolated from my AC supply
I'm working on a project to provide remote control for model trains. The trains I am using are AC powered with approximately 0-20VAC applied to the rails. They have two features: directional control ...
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How to offset a 15 VDC signal to be visible on the scale of 50 mV?
I'd like to watch the output from a power supply to evaluate noise and distortion. The output is 15 VDC.
Unfortunately, when I zoom in to 50 mV per division, the signal is off the scale. I'm using ...
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3
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How does this LLC converter keep 50% duty cycle and zero DC offset with AC-coupled feedback?
I'm currently designing an LLC resonant DC/DC converter with 12V input, +/-15V output and nominal 200W combined output power. I've already got my resonant circuit, transformer, gain curves and power ...
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406
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Unwanted DC offset at the input of inverting op-amp
I'm designing an envelope generator for a sort of mini synthesizer I'm currently working on. I want the envelope signal to evolve (rise or decay, depending on the SPDT switch) only when the switch (...
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How does the offset correction work in this circuit?
I'm reading a paper about a received signal strength indicator (RSSI) amplifier. The amplifier was to estimate the relative power of the input signal, and was designed by cascading 6 limiting ...
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265
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How is DC bias offset removed in a differential amplifier circuit?
Looking at the long-tailed pair, if we remove the dual supply and bias the amplifier for single supply operation it will generate a DC-shifted signal. How is this DC-offset typically cancelled for ...
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DC offset of DC signal with op-amp
I have a DC signal from a DAC in the range of [0:3,3]V and want to convert it to be in the range [-5:5]V. My approach would be to scale with op-amp with gain 3 and then DC offset.
I've read that this ...
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What could be the cause of a constant voltage offset on the STM32L041G6 ADC?
I have been testing the ADC on my STM32L0 with 12-bit resolution and for some reason, every measurement I take has a 0.048 V offset. I've tried a different supply voltage (from 1.8 V to 3.3 V), but ...
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What is the reference voltage of Vin- and Vin+ in this circuit?
I'm trying to make a PCB board to measure Electrocardiogram (ECG) signal. I have some doubts about the DC offset of the 2 input signals (\$V_{IN-}\$, \$V_{IN+}\$) with reference to analog ground. I ...
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Calculating offset voltage [closed]
This is a circuit that is in my textbook, the derivation for the offset voltage is not provided only the end result is. I would really appreciate it if someone could please help explain how this is ...
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How do I calculate a voltage divider with an offset
I've got the following circuit:
simulate this circuit – Schematic created using CircuitLab
By running the simulation I can see that a signal voltage of 3.13 converts to an output of 2.14, but I'...
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DC offset and amplifier
I have a very small AC signal from a receiver coil of Metal Detector that I want to provide some DC offset so it can be handled by a microcontroller after it is amplified. I came up with this solution....
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Removing DC offset in MATLAB
My teacher has a demodulated signal and he removed the DC offset with this one line of code in MATLAB:
y_dc = y - mean(y)
Can someone please explain how this line ...
user279216
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Measure dynamic comparator's offset voltage
I'm trying to characterize a comparator I built and I am wondering how I can plot offset voltage over time. I would like to eventually add a calibration block that will reduce the comparator offset ...
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Confusion regarding term "offset"?
I am confused regarding term "offset".
What is its meaning in context of function generator and oscilloscope?
I have tried to google, but I get results in context of op amp and some results ...
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Why is it important to eliminate ground-shift at the ground of a microcontroller?
I've asked a question about differential amplifiers and their uses in measuring current through a shunt.
In doing so, lots of people advised me not to sense current on the low-side since that can ...
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How does this DC offset sinwave input work?
I have learned that this circuit will move the sin wave up to a DC points due to the voltage divider, that is:
V_out = V_in + Vcc*R2/(R1+R2)
I was using LTSpice to simulate this and it works, I try to ...
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Is using a passive RC high pass filter at the output of an opamp a good method to remove DC offset?
All the information I am able to find related to this discuss about AC coupling the inputs of an amplifier but never the output. I wish to know if there are any issues with AC coupling at the output. ...
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How to block DC offset voltage on a potentiostat output?
I have an AUTOLAB potentiostat: working electrode (WE, Pt wire), counter electrode (CE, Pt wire), reference electrode (RE, Ag/AgCl solid state).
I would like to capacitively couple the potentiostat ...
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How to implement gain and offset in a single opamp?
I tried designer here in this page. But my particular case (Case 2) seems not working in the page.
Then I Read this document and my case there, is section 4. But my calculation results are not ...
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Remove DC comp offset of AC current
I am attempting to build a circuit that excites a sensor which requires an AC current of ±1mA and 20kHz frequency. For this, I used voltage to current converter integrated circuit XTR110, which is ...
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Unkown DC offset of an isolation amplifier circuit design
I am designing an isolation amplifier that consists of the following blocks:
A comparator which produces a PWM signal
A coupling capacitor that achieves galvanic isolation
A voltage follower that ...
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3
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142
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Low-frequency high.pass filter drifts with temperature
for a phase sensitive measurement, I would like to have the DC offset of a signal cancelled. The AC-signal will be amplified and then the phase of it is measured in reference to another AC-signal.
My ...
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Accurately amplifying a number of current sense transformers
I've got 16 current sense transformers that are being used to monitor AC loads. The SCTs are current output type, producing 50mA on a 100A load. The maximum burden resistance is 10Ω, thus the voltage ...
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What kind of op-amp circuit is this?
I am trying to understand the circuit have shown below. As far as I tried, it seems a differential amplifier for me. So, I tried to solve it in the way we deal with DC signals. But I failed to solve ...
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Wheatstone bridge to create offset
While comparing schematics of two old analog oscilloscopes (Tektronix 475 and Goldstar 9020,) I was expecting many differences to get better frequency response since the first is a 250MHz and the ...
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Sawtooth VCO DC offset issues
[Apologies in advance for possible misuse of terminology. I don't have any formal education in EE and am mostly self taught, so I may be lacking in some fundamentals.]
I am trying to design a discrete ...
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What is the practical difference in this DC offset remover?
I am working on audio signal oscillators. My oscillator generates 0V to +5V triangle wave.
Then I'm removing DC bias to get -5V to +5V signal.
I have found two examples on how to do this:
What is the ...
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high voltage DC biasing on top of low voltage AC with floating load
I am in process of designing a power supply for heating a filament in an electron gun. The AC heating current has to float on top of DC high voltage acceleration voltage. The following circuit seems ...
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Meanwell Led driver: internal 3-in-1 dimming circuit
In Meanwell led drivers like the ones from the XLM, HLG or LCM families, how does the internal circuitry for the 3-in-1 dimming feature (0-10V, 10V PWM, 0-100kOhm) look like?
I use a LCM-25 in my ...
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ua741 DC offset on the output
I have ua741cn and connected it to 10V.
V_+ =10V
V_- =GND
Just to verify I have a valid chip I did a little test.
I connected the non-inverting input to GND and the inverting to 10V I would expect the ...
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DC offset before signal being fed into an instrumentation amplifier from a bio potential source
I am trying to design an instrumentation amplifier, having 2 bio-potential sources as its differential inputs, each having peaks in the order of 10's of uV and a frequency band of 3-50 Hz. One of the ...
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Is there a reason the offset of this opamp is done like this?
I recently found this schematic from a project at university (drawn by our lecturer). It's a low pass filter that also adjusts the gain, and adds an offset of 1.5 V (the input signal can be positive ...
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What is causing the DC Offset in Mirrored Howland Current Pump Circuit
I am creating a current source to try to expand my knowledge about electronics design. After some research I decided to build the Howland setup since I want to develop a bipolar current source. The ...
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OpAmp Spice Model: Offset vs Common Mode Voltage
The spice Model of the OPA350 specifies that the DC Offset Voltage vs Input Common Mode voltage is implemented in the model. If I do the simulation however, all I can see is a linear trace, when x ...
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bias a signal with DC input coupling, but without attenuation?
I want to bias the analog signal present on an MCU output pin. This signal varies between 0v and ≃3V, I need to shift it down to -/+1.5V range. Most importantly, I need to keep any DC offset ...
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Why do we need differential amplifier after Transimpedance amplifier?
I am implementing the circuit published in AN3025 Transimpedance Amplifier Design as shown below.
When I am simulating this circuit, a few questions come to mind:
Q1. Why do we need a differential ...
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Offset and scale a DAC output with opamps
I am trying to make a simple oscillator controller with an arduino and a DAC, to learn electronics.
I need to send a voltage between 12V and 17V to my oscillator to control its frequency. I got a 24V ...
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DC offset for AC signal
Hi guys, I am looking for some clarification regarding how to create a DC offset for an AC signal. Attached to this post is a quick schematic that I have drawn. Am I correct in saying that by ...
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Adding DC offset to PWM through a unity gain buffer
I have a PWM signal with a period of 200uS and a duty cycle of 20%. For prototyping reasons (this is simulating a pulse that I'll be receiving from circuitry later on in the project), I want to read ...
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Large signal with DC offset matching to ADC with input centered around 0V
I'm new to this forum, so plear bear with me.
I have a 0 to 23v signal coming from a transimpedance amplifier that I need to squeeze into -2.5v to 2.5v input for an ADC. The signal is first put into ...
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Circuit to adjust -30V to +30V input to 0 to 3.3V for ADC? [duplicate]
Currently working on an oscilloscope design that would require each channel to be able to take in between 30VPP, -30V to +30V, which will go to an ADC which has a maximum input of 3.3V.
What types of ...
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How to remove DC offset (and make average DC value 0V) from ADS1261 square wave AC-excitation circuit
I am attempting to remove the DC offset from the 1 kHz, ± 2.5 V, AC square wave output pins of an ADS1261 (http://www.ti.com/lit/ds/symlink/ads1261.pdf). However, when measured on the oscilloscope (...
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AD620 reference terminal problem
I'm trying to add a DC offset level to a sine signal through an instrumentation amplifier (as the figure below shows.)
The problem is that, in the simulation, everything works perfectly, however, in ...
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Does driving a speaker with a DC offset AC signal matter?
Do these two input signals have different effects on a speaker?
An AC signal with some value of DC offset.
Same AC signal but centered at 0 V.
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Single supply inverting OP amp. Problem: half signal at output
I have built a simple inverting amplifier circuit with LM4565 operational amplifier. But only half of the signal appears at the output of the circuit and the gain looks wrong as well. Could anyone ...
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