operational amplifier

  1. Samaze123

    Why my operational amplifier TL3472IDR doesn't work properly with 1Mhz ?

    On a breadboard i'm using an Arduino Nano to produce a square signal of 1Mhz. I pass it through a volage divider to keep 1V. Until here all is working properly. Then i use my op amp TL3472IDR to make a volage follower. The op amp can't produce a correct signal and using a scope i'm seeing that...
  2. Younes Thabet

    what kind of noise can be introduced in an OPAMP conditioning circuit?

    Hello all, I have 2 almost similar PCBs for voltage and current measurement. I have used 230VAC from the outlet to test them both. The circuit in both boards is similar which is just a voltage divider to reduce the input voltage (see attached image). but I got some noise in one of them even...
  3. S

    OPA4990IDR Getting too hot

    Hi all. I have designed a PCB using the OPA4990IDR op amp in a comparator configuration. I have use the OPA as a unity gain buffer also before the comparators. The purpose of this PCB is to measure battery voltages of up to 10 Li-Ion cells (3.3V each , 38V MAX). I am having a problem tho...
  4. J

    folded cascode op ampdesign

    Hello, I'm trying to design a folded cascode op amp as shown below. I need a high full power bandwidth, about 90 to 100MHz, and a high gain (>60dB). I reach the required gain but it's hard for me to have a large full power BDW, it doesn't exceed the 500KHz. From the theory, the frequency at...
  5. J

    PSRR in op amp

    Hello, I have a question about the PSRR and the noise in an op amp. Which configuration has the best PSRR? Is it the telescopic one or the folded cascode? I know that to improve PSRR, we need to have a high output resistance and symmetric architecture ( can someone pls tell me why symmetry...
  6. J

    Operational amplifier MOSFET vs BJT

    Hello, I have a question regarding operational amplifiers. Whenever I search for some datasheets of high gain and high-speed Op Amps ( BW higher than 50MHz), I mostly find that they are made of bipolar transistors rather than mosfet. Why is it so? I've done some research and I've found that...
  7. J

    operational amplifier design

    Hello, I'm trying to design an one stage OP AMP made of a differential pair, a current load and a current mirror as shown in the picture ( the first stage only, I didn't include Q7 Q6 and Compensation capacitance) I designed the circuit to have a gain of 100V/V, a slew rate of 2V/µs, aGWB...
  8. hulage

    Sample and hold circuit simulation in Altium

    I'm done getting crap output signals. I've tried to simulate about a dozen circuits with several operational amplifiers. Filters work fine, but SAH doesn't. I give up and asking you for help. There can I find tutorials about designing circuits with OP AMPs? Also, if you got a circuit, you are...
  9. P

    OPA657 Op-Amp oscillating for unknown reasons

    Greetings, I am working on a Lidar system for a senior project and am running into issues I am unable to solve with my circuit. The project requires the use of an amplification and comparator circuit in order to take the detector output up to a level that will trigger a TDC controlled by a...
  10. alifaqil25

    What is the important of Gain Bandwidth of op amp

    Hello, I am required to design an active band pass filter and I needs to design it at high frequency around FM Radio frequency (>80MHz). Do the GBW of op amp needs to be selected accordingly to the required frequency or it does not matter? And what is GBW indicates actually?
  11. R

    DC biased opamp input resistor function

    http://www.generalguitargadgets.com/pdf/ggg_dist_plus_sc.pdf I'm looking to understand this schematic. Currently focussing on the input and power stages. Here's where I'm at: INPUT R1 is a pulldown resistor. It provides a path for the leakage current through C2 when the switch is in the...
  12. R

    Op-Amp Voltage Follower Outputs ~+Vcc when IN+ is 0V

    Hi all, I'm fairly new to working with operational amplifiers and so I'm just messing around with a few basic circuits. Had a comparator working fine to switch an LED on/off based on some variable reference voltage, but now I'm trying to get a working voltage follower. I have 2 different...
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