Op-amp circuits and noise at high frequency/low amplitude

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SUMMARY

The discussion focuses on amplifying a low input voltage of 1nA at frequencies between 10kHz and 1MHz using operational amplifiers (op-amps). Users are seeking techniques to minimize noise in their amplification setup, which includes a function generator, oscilloscope, and passive components. Key points include the limitations of bandpass and high-pass filters in reducing noise and the impact of op-amp characteristics on performance at high frequencies. The conversation highlights the need for advanced noise reduction strategies beyond basic filtering methods.

PREREQUISITES
  • Understanding of operational amplifier (op-amp) configurations
  • Knowledge of high-frequency signal amplification techniques
  • Familiarity with noise reduction methods in electronic circuits
  • Experience with passive components such as resistors and capacitors
NEXT STEPS
  • Research advanced noise reduction techniques for op-amp circuits
  • Learn about the characteristics and selection of op-amps for high-frequency applications
  • Explore the design and implementation of active filters for noise management
  • Investigate the use of shielding and grounding techniques to minimize electromagnetic interference
USEFUL FOR

Electronics engineers, circuit designers, and researchers working on high-frequency signal amplification and noise reduction in op-amp circuits.

GuitarOfWar
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Hi everyone.

I am tasked with amplifying an input voltage of around 1nA at anywhere between 10,000kHz to 1MHz to a sufficient amount. We've been using op-amps in multiple stages in series to amplify the signal. At our disposal we have a function generator, oscilloscope, breadboard and resistors, capacitors etc. Are there any tricks or techniques I can use to reduce the noise from the op-amps?
 
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GuitarOfWar said:
I can't bandpass the signal because the input is meant to be simulating particles hitting a plate at a frequency of say 10000kHz to 1MHz.

You're wrong. it sounds like you have a false idea of what bandpass filter means. The word "band" means a range of frequencies, such as 10kHz-1MHz.
 
anorlunda said:
You're wrong. it sounds like you have a false idea of what bandpass filter means. The word "band" means a range of frequencies, such as 10kHz-1MHz.
Doesn't the op amp kind of work as a low pass filter? At frequencies about 1.5-2MHz+ the gain starts decreasing any way. Also we tried using high-pass filter with an RC circuit that only allows frequencies above 10,000kHz to pass and the amount of noise reduced wasn't dramatic. Is there any other tricks I can use to eliminate noise which aren't just using a filter or is my task limited by the type of op-amp I am using?
 
I posted an answer in the original thread.
 

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