noise lecture

Feb 26, 2019 0 Replies

I'm giving my kids a little lecture on noise this afternoon. Here's my outline.



Did I miss anything?


Noise In Electronics Notes



JL Feb 25, 2019


Conductors, atoms, electrons



Johnson/Nyquist noise Ej = sqrt(4KTRB) RMS Power, voltage, current Flat finite spectrum CoE Equivalent thermal conductivity The sky is cold



Shot noise Is = sqrt(2qI) RMS Not in metallic conductors, maybe in cermets/carbon In semi junctions, base currents, photodiode currents Worse in PMTs and APDs PMTs as radar jammers



Excess noise 1/f flicker grain boundaries pentode grid partition tempco driven



Thermal noises Resistor tempco Air flow turbulance Thermoelectrics



Piezo noise, mostly caps



Magnetic loop pickup



Opamps Voltage and current noise PSRR RF rectification



Bipolar transistors Rb



Jfets



CMOS Popcorn noise



Fans Vibration Mag fields E fields from blades power supply ripple



RF Junction rectification Digital logic spikes TV, cell phones Sutro tower Fluorescent lights, motor controllers



PSRR Can be worse than 0 dB Watch DC, too



IC photo sensitivity chip-scale stuff



Ground loops Many goofy theories about grounds and shielding Differential is best



Zeners and noise diodes



Gas discharge devices Noise tubes in magnetic fields Neons in waveguides



Noise figure meters



Noise makes jitter


Spice No noise analysis in time domain Can cheat



PCB layout



John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com http://www.highlandtechnology.com

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