# opamp

1. ### Reduce noise from OP Amp + Low pass filter for accelerometer data

Hello, I'm beginer in amplifier circuit and filter circut. I'm working on a project that detects small vibrations from larvae inside tree trunk, I am inspired by this research ( Sensors | Free Full-Text | In-Vivo Vibroacoustic Surveillance of Trees in the Context of the IoT (mdpi.com) ). The...
2. ### what is the purpose of opamps in high voltage sensing?

Hello all, I have an inverter stage that I need to monitor its output voltage, a friend suggested the circuit below but I didn't understand how it works and why he chooses these values in particular. What circuit do the opamps form? What would the output look like? What is the purpose of the...
3. ### Problem with current sense circuit using opamp

Hi, I am a beginner in hardware design. Recently got a task to design a simple current measurement device. The device should have only 3 states: Current is lower than 10 mA Current is between 10 and 100 mA Current is higher than 100 mA For current measurement I am using a LM358N op amp in a...
4. ### Need help with identifying the topology of this Amplifier Circuit

What is the purpose of this circuit?
5. ### DIY Microphone suggestions

So I recently saw a video from DYI perks and he uses a "TSB-2555B Electret Capsule" and a "THAT1510". However, building my own pre-amp seems like a daunting task and I don't have the budget to buy a kit from somewhere like mic parts. So if anyone has suggestions as to a simplified pre-amp or a...
6. ### Need help understanding this LDO topology

I'm trying to understand how a LDO topology works. It's in NXP IC's datasheet: It has the control circuitry inside the IC with external transistor. Parameters: VDD output = 1.8V Collector supply = 2.367V NPN: Nexperia PBSS4620PA L1: ferrite bead 26 Ohm @ 100MHz C1 = 470nF Rp = 1 Ohm Rs = 0.15...
7. ### High side Current Sensing with opamps

, I am trying to make overcurrent protection circuit using opamps with shunt resistor. But when I increase my main voltage my current must directly increase and comparator opamp compare the input voltage and Vref voltage if Vin greater than Vref than my mosfet must be triggered and close the...
8. ### Design review: Fully differential telescopic Operational amplifier.

Hello, I used Behzad Razavi's book to design a fully differential telescopic op-amp [screenshot attached]. Then I follow the same steps to design my proposed opamp, but I am not getting the desired result. Can someone point out where I'm doing mistakes? For your reference, I have attached hand...
9. ### Multiple current sensors in parallel using opamps

Hello, I'm making a workbench DC power supply monitor, with a current sensor for each voltage source, using LM324 opamps. The sensors work well alone, however they seem to measure not only the current on their source but also the currents on the others, so I can't measure the current on each...
10. ### Failed diode function generator

Why would a diode function generator output a distorted waveform at high frequencies(>50kHz)? In theory and simulation, it should be fine, but when testing, the diode fails to perform properly at higher frequencies. Any ideas?
11. ### Generate triangle wave with phase shift from square wave

Hi all, I am trying to simulate the circuit above in LT Spice but the output is not the same . It can be found here . What mistake have I made :) ? I have attached my LT Spice zip in the folder below for easy amendment. Thank you
12. ### Output of OP-Amp circuits

Could really use some help with this, thank you all :)
13. ### DIY Microphone - THAT1510 or THAT 1512

Dear all, As a reference to the context why I'm asking this question: I'm looking for the THAT1512 but it's hard to find and often the 20€ delivery is quite expensive for a 5€ part. Moreover, the THAT1512 seems to be out of stock in a lot of places until June 2022. I'm looking for an...
14. ### Op amp used in cyclic voltammetry application

In cyclic voltammetry application (as per circuit design given in image), the voltage difference between reference electrode (RE) and working electrode (WE) will be constant. As per REDOX process (Reduction & Oxidation), the current will flow between counter and working electrode. The circuit...
15. ### Regulate voltage using op amp

Hi readers, I am doing an Op Amp voltage regulation of voltage drop across load. As you can see from diagram, I have a fluctuating_Vin (0V to 50V) and I want the voltage drop at load (100 Ohms) to be the same (14V) at all times no matter whether input voltage is 20V or 30V or 50V? Note: I...
16. ### Convert triangle wave to sine wave.

Hi readers, the IN node has triangular wave converted from square wave pulse. This Op-Amp acts as integrator. However, when I attach the same integrator circuit to convert this triangular wave (IN) to sine wave, the Output (OUT) I got is still quite triangular and not quite a good sine wave...
17. ### Ripples in square wave output of LM7171 high speed OpAmp.

I am trying to change the voltage level of a 10MHz clock signal. For this I am using LM7171 as a non-inverting summing amplifier, to DC shift the input signal, with some positive gain to reach the required voltage levels. The circuit has been soldered on a general purpose PCB and is operating at...
18. ### DC current sense using Opamp

I want to measure a current consumption for DC fan. I am using OPA2197 opamp for the same. Following is the circuit diagram. i want to understand if this circuit missing anything?
19. ### Dimmer Circuit Simulation Problem

Hi I am trying to make a dimmer circuit with proteus. But it is not working according to our calculations. I am very new both in proteus and also learning about OP-AMPs. So I am not understanding what's wrong with the schematics. Both the current and voltage is showing zero. Here is the...
20. ### Parallel Inverting Summing Amplifiers

Hello Everyone, To add on to my newbness from yesterday, I have one other part of my design that I am not sure what's going on. I have some suspicions but thought you guys probably could spot it pretty quickly or at least probe at me to look at it differently. I have again attached a setup...