guidance on the circuit analysis

Low Noise Single Supply Photodiode Amplifier

I am trying to understand the circuit shown above, with one JFET transistor at left side acting a current buffer and right hand side with a op amp.

this is a low noise transimpedance circuit,  which I think I can use or modified this circuit and used in my design, sensitive to noise and a current signal needed to be amplified to voltage signal in the end. 

the problem is that I am not quit sure how to analyse the circuit, should I use small-signal analysis? Do I need to derive the transfer function? 

why the Bandwidth is 2MHZ and where is the cut off frequency? and is the system stable or not? 

Can someone give me a clue or answer, please? 

Thanks

Parents
  • Hey Walt

    Thank you for your reply, book and tutorials. currently I am doing a university project, we created  a sensor for sensing the sound wave, but current out signal from sensor is very sensitive to noise. I need to choose a Low noise amplifier.

    this circuit seems like a suitable opinions, I would like to modify this circuit by changing the amplifier of LTC6252 to a low noise amplifier, and then change the resistance value, capacitor value in order to get rid of the frequency below 20HZ and above 20KHZ, also with a high gain.

    and How can able to know its cut off frequency from the circuit? and even I use low noise amplifier, how can I maintain the external circuit noise? do you have any reference I  can read?

    Thanks so much for your help

    Muyuan wang

Reply
  • Hey Walt

    Thank you for your reply, book and tutorials. currently I am doing a university project, we created  a sensor for sensing the sound wave, but current out signal from sensor is very sensitive to noise. I need to choose a Low noise amplifier.

    this circuit seems like a suitable opinions, I would like to modify this circuit by changing the amplifier of LTC6252 to a low noise amplifier, and then change the resistance value, capacitor value in order to get rid of the frequency below 20HZ and above 20KHZ, also with a high gain.

    and How can able to know its cut off frequency from the circuit? and even I use low noise amplifier, how can I maintain the external circuit noise? do you have any reference I  can read?

    Thanks so much for your help

    Muyuan wang

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