Posts tagged opamp
Synonyms: opamps operational-amplifier operational-amplifiers op-amp op-amps
I need to make a circuit board that has the following inputs and outputs: Inputs and outputs Inputs: $V_{\text{in1}}$ (0-10VDC) PLC controlled signal $V_{\text{in2}}$ (0-10VDC) PLC controll...
I’m looking for circuits which convert differential current signal into single ended voltage. If found two topologies in application notes, and though of one more [obvious] topology myself. How d...
I was looking for electret condenser microphone preamp topologies. I’d like the preamp to run on a single supply, so I’ll have to introduce an output offset. Saw two topologies for introducing th...
I have a photodiode and I want to connect it to an ADC to read the ambient light. For the context, non linearity is not an issue as I'm interested in knowing the amount of light in 3-4 levels. The...
I’ve a linear sensor array (broadside). The array is 10m long and it contains 20 sensors. There’s a limit on the number of wires. I can have a handful of wires running the length of the array, b...
How does this circuit work, especially considering that it's intended to be used as a PT100 conditioner?
Looking at Texas Instruments opamp OPA2211it mentions GBW of 80MHz at a gain of 100, and 45MHz at gain of 1: Looking at the bandwidth graph from Figure 10 in datasheet: It looks like 80MHz is...
I am reading through a multi-channel power supply manual and at some point it discusses the ability to chain channels in parallel to increase current output. In the schematic, there is one resisto...
I benchtested below 0.7A constant current source circuit and observed few cycles of oscillation on drain current. With the help of bode plot analysis , I have managed to reduce the oscillations on ...
*Learning about EMG as a part of our research. My team has at least some experience with electronics that is worth mentioning, but don't have any experience with EMG/bio-potentials. Most EMG hardwa...
EMG consists of an electrode gel skin interface, op-amps with a certain gain and an ADC. Question is in the context of passive electrodes. What are the essential safety features of such types of h...
In EMG there is a certain level of thermal noise created at the electrode-gel-skin interface which depends on the skin-electrode impedance (also known as source impedance). I have been able get th...
I have just started learning about thermal noise in op-amps and while studying could not find if the noise given in op-amps data sheets is random sample to sample regardless of the time interval be...
Here is the bootstrapping technique for opamps, as exposed in the Art of Electronics:. This technique is supposed to increase considerably the input impedance of the opamp for an AC input source (...
More about the circuit The circuit is sensing (low side sensing for many reasons) current used to power up the lights with 28V(part of the schematics not shown here -> relay with LC filter ...
This application note from Linear Technology discusses oscillations in opamp circuits and some compensation schemes. One method discussed for reducing phase shifts in the loop gain due to the RC ne...
What is your best suggestion for building a follower that would ideally satisfy the following spec: frequency: from 100 Hz (or lower) to 1 GHz input signal impedance: 1 Mohm input signal ampli...
Inside a op-amp after the stage where the differential signal is converted to single ended , there is further amplification of the DC signal.For AC signals there is a capacitor parallel to the tran...
I am planning to use the LM318 operational amplifier to generate a PWM signal and I need to know how to calculate the rise/fall time. LM318/LM218/LM118 datasheet -The slew rate is 70 V/µs maximum...
Once in a while in literature I see a DC offset subtraction loop. Here are a few more examples. DC servo loop removes a DC offset after an op-amp. DC servo loop removes DC current from a photo...
I understand that white noise is not always Gaussian. In general, is the $V_{pp}$ and $V_{RMS}$ noise stated in operational amplifier and ADC datasheets Gaussian? And is its mean zero? Any exemptio...
1- What we call this opamp configuration? 2- What's the advantage and the disadvantage of this circuit? 3- And what's the purpose of the L2 in the feedback? I have changed gradually the value of...
Im designing a Hartley oscillator this time with a opamp providing the open-loop gain.I have tried drawing the small-signal analysis of my circuit to use KVL and KCL to find the conditions of opera...
I'm designing a high side current source that can be controlled with a Digital-to-analog and can source up to 100mA with voltage supply up to 36V. By high side I mean one side of load will be alwa...
I am designing a DC/DC converter in the control loop of which a transconductance amplifier (OTA) is used. This part of circuit looks like this: To determine the needed characteristics, I am usin...
In noise analysis of operational amplifiers, the following is considered: Noise generated by the external components (resistors in feedback network etc.) Noise generated by the operational ampl...
In the image below is an opamp buffer with +/- 15v rails connected to a 3.3v ADC. The input to the opamp is limited to 0-3v. There is no protection circuitry for the ADC. Is the risk of the opam...
Hi, I built a constant current load following the circuit from https://www.instructables.com/id/DIY-Constant-current-load/ But my op amp gets destroyed after a few minutes. The transistor or the op...
I've built a non-inverting op-amp amplifier with a gain of 101 using this circuit: - My input is 10 mV DC and I expected to measure 1.01 volts at the output but I measure 0.81 volts. What has happ...