Questions tagged [input-offset-voltage]
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2answers
122 views
Offset voltage comes to saturation in coupling amplifier circuit using OpAmp with Gain=100
I did get in troubles with my student project circuit below!
The purpose is to amplify difference between two inputs. Specifically, 20mV and 10mV are connected with input to get 1V at the last OpAmp'...
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1answer
33 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 ...
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1answer
61 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 +...
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0answers
50 views
Comparing sine wave and triangular for spwm using comparator
i am trying to generate sinusoidal PWM by comparing sine and triangular wave.
First i just tried to compare sine wave with reference voltage in order to check the working of op-amp. I get a problem ...
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2answers
49 views
Input Bias Compensation Resistor Calculation for an Integrator
I have been reading the following tech note from Analog Devices that discusses designing an op amp circuit to compensate for the input bias current: https://www.analog.com/media/en/training-seminars/...
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0answers
50 views
How to solve practical OPAMP with finite differential resistance and finite offset current while other parameters can be considered ideal?
simulate this circuit – Schematic created using CircuitLab
Ip(bias)=200nA
rd=differential resistance=5Mohm
a=infinite
What should be its output?
I am confused if I should consider negative ...
0
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1answer
81 views
What is role of R9 resistor at input to OPAMP in this circuit?
I guess it has to something with offset nulling but not getting how .Circuit shown is of instrumentation amplifier.
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1answer
64 views
Op Amp Input Offset Voltage vs Common Mode Voltage
I would like to use an op amp AD8618 for a design, and need the input offset voltage to be low. For this op amp it seems fine with maximum of 65uV, but looking at the charts on page 6 etc, it seems to ...
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1answer
23 views
sensor output level shifter
I am trying to read a map sensor with an ads1232 ADC.
The Map sensor requires 0v(ground) and 5v+ and outputs 2.5v fluctuating +-2.5v depending on the pressure. The ads1232 can read +-2.5v but without ...
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2answers
64 views
opamp Vos bias resistor
In a simple inverting amplifier I've seen the below topology in my text book, where R3 is said to be R3=R1||R2.
However, every time I see this, all three resistors are the same values! From Forest ...
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2answers
55 views
op-amp pin is sitting at high voltage (active low-pass filter)
I am looking at using the OP1177 to act as an active low pass filter. I need to smooth out a 20kHz signal burst with a minimum of 50 cycles to reach a voltage on the output to interrupt an ...
0
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1answer
74 views
Input offset voltage for microphone circuit
Does anyone know what's the input offset voltage (oscillated 2.5V) to the op-amp in the circuit for? From my understanding, the input offset voltage needs to be extremely small so that output DC ...
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2answers
304 views
Supply Voltages for Inverting Amplifier
I want to use an inverting amplifier to linearly shift and convert a signal with voltage range -10...+10V into 0 ... 3.3V for an ADC of a microcontroller. I wanted to use the circuit presented in this ...
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2answers
538 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? ...
2
votes
1answer
259 views
Compensating for offset voltage in bridge measurement before instrumentation amplifier
I'm using an instrumentation amplifier (INA118) to measure the signal from a full bridge strain gauge (tension only, all 4 resistive elements are strain gauges, slow changing (DC) signal). I'm using a ...
0
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1answer
415 views
input offset voltage of an op amp
How input offset voltage (2mV max) will effect input which is at 0.5mV and 0.5 to 5Hz frequency? The input voltage and frequency are of heart vibrations which will be very low.
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4answers
289 views
Do AC coupled inputs suppress voltage offsets in an op amp?
Background: I'm trying to build an AC coupled pre-amplifier that doesn't succumb to voltage offsets and input bias currents. The input signal has noise ~10 nV level, and I want a factor of a million ...
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2answers
266 views
Strange voltage tracking problem with regulated power supply build
I'm building my own regulated linear DC power supply based on the Farnell L30 (service manual and circuit diagram here) and I'm sticking mainly to the original design with some modifications for parts ...
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3answers
1k views
Measuring input-offset-voltage of an opamp in sim and getting very different result in datasheet
With the definition of "input offset voltage" I wanted to find it in simulation for LM358 op amp. Here is the definition: "Input offset voltage is the differential input voltage that would have to be ...
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1answer
160 views
Combined temperature coefficient of LM741 and trimmer pot for null offset
I want to use a 10k trimmer pot with a 250ppm/°C tempco for offsetting input offset voltage of an LM741 op-amp.
Cermet potentiometer temperature coefficients partially answers my question. And the ...
