Alessandro95
Newbie level 4
Hello all,
I am currently designing some pixel circuits for my bachelor thesis and am trying to analyse the noise of such a pixel using Cadence. I have a couple of questions regarding this aspect as I am new to this..
Also please consider that the pixel is a black box (made up of a photodiode and transistors) whose input ports are some logic signals used for selection and a photodiode input light intensity. For the output I have a voltage signal, say Vout. I am using ADE and selecting a noise simulation sweeping the frequency to obtain the power spectral density function and then integrating the range I require to determine the total noise output.
1) Is the correct way of doing noise analysis of a circuit?
2) I am assuming that any dynamic noise measurements for example kTC noise and such are not included in the simulation. Is it right to assume this?
3) Moreover I get a plot which seems to include 1/f noise (the noise power increases and then drops proportionally to 1/f at around 22Hz).. Are the standard models such as NMOS4 and such valid for >20Hz or so? (sorry this might be a daunting question since I have not seen any information regarding the noise model for NMOS4)
4) I also get a total noise voltage of around 0.5V which to me seems a bit high.. so again I ask if this methodology correct so that I can try to perform further tests in order to justify this value
Thank you for help,
Alessandro
I am currently designing some pixel circuits for my bachelor thesis and am trying to analyse the noise of such a pixel using Cadence. I have a couple of questions regarding this aspect as I am new to this..
Also please consider that the pixel is a black box (made up of a photodiode and transistors) whose input ports are some logic signals used for selection and a photodiode input light intensity. For the output I have a voltage signal, say Vout. I am using ADE and selecting a noise simulation sweeping the frequency to obtain the power spectral density function and then integrating the range I require to determine the total noise output.
1) Is the correct way of doing noise analysis of a circuit?
2) I am assuming that any dynamic noise measurements for example kTC noise and such are not included in the simulation. Is it right to assume this?
3) Moreover I get a plot which seems to include 1/f noise (the noise power increases and then drops proportionally to 1/f at around 22Hz).. Are the standard models such as NMOS4 and such valid for >20Hz or so? (sorry this might be a daunting question since I have not seen any information regarding the noise model for NMOS4)
4) I also get a total noise voltage of around 0.5V which to me seems a bit high.. so again I ask if this methodology correct so that I can try to perform further tests in order to justify this value
Thank you for help,
Alessandro