# opamps

1. ### Symmetric Output Sensors (Help)

A sensor works by outputting a voltage of -400mV to +400mV with a impedance of 1M Ohm. a. Design and simulate a circuit that only uses active components, such as an in the form of an OP-AMP so that the output reads 0V to 5V. Create the circuit in LTspice. Can anyone help me with this topic...
2. ### Dual Power supply with Opamp and 9V battery

First of all I would like to say that I am very newbie in this electronic design. So please don't get upset if this question is too stupid. I am designing a circuit with opamps that can provide +3V and -3V and that can deliver 0.5 Amps. I know I can use the Lm317 and Lm337 but this time I would...
3. ### 4-20ma to 0-3.3V conversion using Rail to rail Opamp

I am trying to convert 4-20 mA current loop signal to 0-3.3/0-3 V output for my 10 bit ADC IC that is connected to a Raspberry pi 3B+. Schematic: The input sensor is a 12 V loop powered 4-20 mA output humidity sensor. The op-amp is an MCP6002 rail-to-rail. The output of the op-amp is...
4. ### Measuring amplified capacitance

Hi all, For a project I need to build a capacitor amplifier, with current boosting, so that rather large currents can flow without the OPAMPS saturating, as the resistance of the circuit is rather low normally, around a few Ohms. The measuring circuit is the following: The R13 resistor is in...
5. ### op amp circuit that calculates grade percentage of a subject

Hello, I need to make an op amp circuit that calculates the grade for a subject, where there are 4 types of grade 35% 10% 20% and 35%, within each percentage it is 0-100 points, so I plan to do this : 100%=10mV Input 0-10mV output 0-3,5mV Input 0-10mV output 0-1mV Input 0-10mV output 0-2mV...
6. ### How does someone can come to this formula in closed loop OpAamp?

Hello Everyone, SO I found this amazing article (part 2) about negative feedback and I love it. how does he come to that the closed-loop cutoff frequency (fC,CL) is related to the open-loop cutoff frequency (fC,OL) as follows: fC,CL=fC,OL(1+ALFβ)
7. ### Output of OP-Amp circuits

Could really use some help with this, thank you all :)
8. ### Choice of error amplifier for LDO

Hi There! I am, for several reasons about building a adjustable LDO. Some of the specifications are: - min input voltage 4.4V - max output voltage 3.6V - 500mV dropout, due to sense resistor - wide current output range - at least 20kHz bandwidth @ 10uA load, ideally 100kHz Pass element shall...
9. ### Non-Inverting Amplifier (AC Coupled) : How to solve this circuit with lower and high frequency?

I need to design this circuit with a gain of 26 for signals where the frequency varies from 800Hz to 8kHz and I also need to find out the current on the RL load. (VA = 100mV) Will C1 behave like an open circuit in ac analysis? I am getting to lower the frequency (800Hz) but I am not able to...
10. ### Finding the closed loop gain expression

Hi! thanks in advance for the help. I'm trying to solve this exercice for school but a really can't seem to get it right. I get really confused when that VDD apperas and can't identify the feedback mesh Here is what i think it is: But then again i'm not sure if that vdd or that resistor...