Questions tagged [dc-offset]
The dc-offset tag has no usage guidance.
94
questions
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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 ...
3
votes
2answers
69 views
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 ...
3
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0answers
81 views
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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0answers
48 views
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 ...
1
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1answer
44 views
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 ...
0
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2answers
61 views
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 ...
0
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1answer
51 views
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 ...
0
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2answers
50 views
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 ...
0
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2answers
52 views
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 ...
0
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2answers
66 views
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 ...
0
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2answers
89 views
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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1answer
76 views
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 ā3V, I need to shift it down to -/+1.5V range. Most importantly, I need to keep any DC offset ...
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1answer
88 views
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 ...
1
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3answers
217 views
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 ...
1
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1answer
248 views
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 ...
0
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3answers
269 views
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 ...
1
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2answers
68 views
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 ...
0
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3answers
166 views
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 ...
0
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1answer
726 views
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, Ā± 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 (...
1
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1answer
68 views
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 ...
14
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2answers
2k views
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.
0
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1answer
105 views
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 ...
1
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1answer
193 views
How to compute DC offset of analog circuit?
I have an analog circuit which has an input voltage range Vin of 5V - 10V and output voltage Vout.
One can assume that the circuit has been simulated and a DC sweep of Vin with a range from -10V to +...
0
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2answers
285 views
Does this Sallen and Key filter work on a single supply and does the input offset matter?
This is the schematic for a Sallen and Key from the Doepfer Musikelektronik website:
simulate this circuit – Schematic created using CircuitLab
I intend to run this in a synth, the oscillators ...
0
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3answers
253 views
AD620 pH probe has a positive voltage offset!
I am a chem eng. but little background in electronics.
I'd like to interface a pH probe with an AD620A, the original PCB that came with pH probe was damaged by a current leak in the solution.
I made ...
0
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1answer
164 views
Waveshare ADC Board changing analog input range [duplicate]
This question has been redirected from raspberry pi community. Some of the questions have been answered by @Milliways, so those questions have been edited out.
I'm using this Raspberry Pi High-...
0
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0answers
83 views
Remove Sensor Voltage Offset ADC [duplicate]
I've got a pressure sensor and a flow sensor. Both have a 5V span, but have a (different) null offset i.e. at zero pressure (gauge) or zero flow they read ~2V and ~1V respectively.
I am using an ...
4
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1answer
241 views
Analog switch on an instrumentation amplifier input
I'm working on a project for school that involves a configurable input stage (AC/DC coupling and variable input impedance) connected to an instrumentation amplifier. I am wondering whether I will ...
0
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1answer
293 views
Single supply opamp colpitts oscillator
I'm designing a Colpitts oscillator with a single supply rail-to-rail opamp powered with 3.3 V. The positive input of the opamp is set to VDD/2 to offset the negative part of the oscillations so ...
0
votes
1answer
464 views
How do I remove the offset from the DAC output and change the range?
This DAC has an output range of 1-3 volts. Here's the datasheet:
Datasheet
I'm getting pulses with different amplitudes, frequencies, duty cycles and widths varying from 0.2 ms to 2 s from the DAC. ...
1
vote
3answers
369 views
Inherent DC Bias in ADC sampling
I was just simulating the quantization behavior of ADCs of different bits, on data sampled by a 24-bit ADC. What I noticed that as we go towards ADCs with less bits a DC bias in the signal becomes ...
0
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1answer
2k views
Op Amp as a simple switch
I want to build a little voltage switch that switches on a buzzer and a relay when a certain voltage is reached. Please have a look at the schematic.
I use a trim potentiometer to set up the switch ...
0
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1answer
250 views
Resistor values for OpAmp circuit with dc offset applied to inverting pin
$$
\newcommand{\rth}{R_{TH}}
\newcommand{\vth}{V_{TH}}
\newcommand{\rf}{R_{F}}
$$
Asked this in the math stack exchange, who recommended asking here instead.
I'm stumped (hence posting here!) with ...
0
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1answer
80 views
What is a good way to add a programable offset to a diffential signal?
I have an AC coupled, ~10 MHz to 1 GHz, differential signal, with a programmable gain, coming from a detector. The signal contain pulses, and the DC-balance is poor but constant (even if my hand ...
1
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0answers
632 views
Audio DC Offset
I want to make an audio processing device using a Teensy and I want to run an analog signal into it. My background is in audio programming, so electronic circuits are new to me. I realise audio is an ...
2
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1answer
112 views
Opamp DC offset Question
Just need some help understanding what's happening in removing the DC offset from two band-pass filters.
VG has a value of 4.5V. When I added in the virtual ground the circuit had an offset of 4.5V ...
1
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1answer
117 views
Unwanted constant offset in ADC reading
I am using an AD7323 12bit+sign 4-channel ADC an on a custom Arduino shield.
I drive it with 12V from a power supply and -12V created using an ICL7662 IC. VCC is 5V from the Arduino.
The ADC is used ...
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1answer
3k views
How to add dc offset and gain to a given signal
Before I start, I just want to mention that I am a premed student. However, I want to build a DIY amp for my headphones since my computer can't properly drive them so I decided to take an electronics ...
0
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4answers
10k views
Adding DC offset to a given input
let me start off by saying I am a computer science student so I'm not familiar with electronics whatsoever. Anyway, I am faced with this problem:
I am given some input (say, a sine wave) centered on ...
0
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3answers
2k views
Ideal integrator op-amp DC offset at output?
i have a question with this ideal op-amp integrator circuit
where R=1k and C=1uF. Then i put a 50mV 100Hz square wave at the input and get the following response, which is what i expected and ...
3
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3answers
645 views
Offsetting a differential amplifier to remove the need for a dual supply
I'm developing two similar circuits that will enable me to differentiate the X and Y coordinates from a segmented photo-diode (Four segments). These coordinates will be dependent upon the position of ...
0
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2answers
1k views
OP-AMP DC offset compensation
I do not know how to compensate the DC-offset caused by the Input bias current.
simulate this circuit – Schematic created using CircuitLab
How to compensate the input current bias DC offset? ...
3
votes
2answers
2k views
How does an inverting op amp add a DC offset?
I'm working on a project based on this publication. I've built the circuit but something is not working.
I've tried checking the voltage with a multimeter (I do not have an oscilloscope at hand) and ...
5
votes
3answers
3k views
How to compensate gain and offset errors
I have an analog circuit which has an offset error as well as an gain error.
I can measure the analog output of the circuit and I am able to manipulate the gain of the circuit by means of a factor <...
0
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1answer
877 views
DC offset of amplifiers for 12V single supply operation
I want to be able to amplify a signal using op-amps and a single power supply. In order for the op-amps to have maximum swing with a 12V power supply the AC input signal needs to be offsetted to 6V.
...
3
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3answers
22k views
Peak to Peak vs. Amplitude
For a sine wave,
Amplitude is the fluctuation or displacement of the wave from its
mean value.
Peak-to-peak (pk-pk) is the difference between the maximum positive
and the maximum negative amplitudes ...
1
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1answer
519 views
Questions about DC offset
As many people on the internet I'm trying to add a DC offset to an audio signal. I've amplified it with an LM324 op-amp, using dual supply (+/- 5V).
Afterwards I'd like to input this audio in my ...
1
vote
3answers
2k views
A question on sizing a blocking capacitor
When I was trying to find an answer for an optimum capacitor value for entire DC removal of a signal I encountered the following:
In general, DC blocking capacitor shall behave like a short at ...
1
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1answer
99 views
I am stuck at a question (about bias current and offset voltage)
So I was doing the following question from sedra smith microelectronics:
I have managed to do all parts in the question except part d. I am stuck at part d.
The way I have tried is the following: ...
0
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1answer
185 views
Miller integrator dc offset ->why no gradual increase towards saturation?
I made a miller integrator with a dc offset. (The initial condition of the capacitor is set to zero so initial condition is not the problem). There is a capacitor or 10-7 F capacitance and a source ...
