Noise is the great limiter. Without it, we could communicate over arbitrarily large distances while consuming almost no power. Unfortunately for us mere mortals, we have to overcome the effects of noise in our world. In this article, we look at the sources of noise in MOS devices. You will learn:
Very interesting summary. What I missed is some line or two concerning the RTN/RTS type of noise (Random Telegraphic Noise). I have discussed lately with some people concerning the design of CMOS ASIC and when I brought up this concept of RTN, they never heard of it. Maybe this is something that is rarely a problem nowadays then???
So, reading between the lines, these modern tiny VLSI CMOS are not the nicest to use for audio or ancient radios like AM or FM? I remember discrete transistors where shot noise was a low rumble in audio range, but now you say the corner might be 100MHz, unreal.
Honestly it is hard to find the flicker noise corner in the latest and greatest nodes. While researching this article, some published papers showed flicker noise up to 1 MHz, and this was for 14nm FinFets. In speaking with some folks in industry, I was told that flicker noise corners are >10 MHz these days, could be higher. Luckily we won't need these fancy technologies for AM/FM radio :)
I'm actually tray to optimise a low noise amplifier based on discrete JFETs (JFE150 from TI). Their current noise is only given at 1KHz, and measurements at higher frequencies show an important increase of the current noise. This effect seams to increase with the canal current making me think of induced Flicker. But I have to recheck my measurements.
Do you know if JFET are also subject to gate induced noise current ?
Very interesting summary. What I missed is some line or two concerning the RTN/RTS type of noise (Random Telegraphic Noise). I have discussed lately with some people concerning the design of CMOS ASIC and when I brought up this concept of RTN, they never heard of it. Maybe this is something that is rarely a problem nowadays then???
No you’re right. RTN should have been included. Thanks for pointing it out.
So, reading between the lines, these modern tiny VLSI CMOS are not the nicest to use for audio or ancient radios like AM or FM? I remember discrete transistors where shot noise was a low rumble in audio range, but now you say the corner might be 100MHz, unreal.
Honestly it is hard to find the flicker noise corner in the latest and greatest nodes. While researching this article, some published papers showed flicker noise up to 1 MHz, and this was for 14nm FinFets. In speaking with some folks in industry, I was told that flicker noise corners are >10 MHz these days, could be higher. Luckily we won't need these fancy technologies for AM/FM radio :)
Hello,
Thank you for this very nice summary !
I'm actually tray to optimise a low noise amplifier based on discrete JFETs (JFE150 from TI). Their current noise is only given at 1KHz, and measurements at higher frequencies show an important increase of the current noise. This effect seams to increase with the canal current making me think of induced Flicker. But I have to recheck my measurements.
Do you know if JFET are also subject to gate induced noise current ?