2022-10-05 10:28 Status: # Component Noise Different components have different amounts of noise. ## Resistor Noise  $v_n^2(f)=4kTR$ where k is Boltzmann's constant. There's no frequency in the equation (white noise independent of frequency). ### Alternative Model  ## Diode Noise  q - electron charge. Also white noise. Shot noise - two separate regions where an electron has to cross a barrier. ## MOSFET Noise  $I_{dn}^2(f)=4kT\frac{2}{3}g_m$ $V_{gn}^2(f)=\frac{K_f}{WLC_{OX}f}$ Where $K_f$ is the flicker noise coefficient. ### Reflecting noise to gate or drain side It is common to lump these noise sources into the drain or gate side of the transistor. using the transfer function $i_D=g_mv_{gs}$, we divide by $g_m^2$ to get the gate referred noise: $V_{gn,Tot}^2(f)=\frac{K_f}{WLC_{OX}f}+4kT\frac{2}{3}\frac{1}{g_m}$  ### Noise Corner Where the flicker noise and white noise are equal.  ## Limits  Divergest in both high and low frequencies (issues for integrating). HF - not an issue because there is always finite capacitance on the output meaning there is a LPF. LF - lower limit is 1/time to turn the device on for (not really an issue in reality). ## Reactive Components  All noiseless! If it has loss - noise! [^1] --- # References [^1]: [vr-4602-wk03-sc08-componentnoise](../../Spaces/University/ELEC4602%20–%20Microelectronics%20Design%20and%20Technology/Lectures/W3/vr-4602-wk03-sc08-componentnoise.mp4)