Refer to Resistor Current Noise Measurement

Excess noise in a resistor is the electrical noise which is in excess of the value predicted by the well-known Johnsson-Nyquist-Thermal noise formula. Excess noise is created as a voltage impressed across a resistor causes electrons to flow through the resistive material.

In some types of resistors, the increase in noise is so significant that the circuit is useless.

Even in "very good" resistors the voltage noise density can increase by 50% over the Johnson-Nyquist-Thermal formula when 1V is impressed across the resistor. More over, the voltage noise density spectrum takes on flicker (1/f) shape as the DC voltage across the resistor is increased.

To the best of my knowledge, there is no SPICE variant with a .NOISE analysis which accounts for excess noise. Is this true?

  • \$\begingroup\$ does excess-noise exhibit a 1/F behavior? \$\endgroup\$ – analogsystemsrf Oct 11 at 3:05
  • \$\begingroup\$ The cited report shows that excess noise exhibits 1/f behavior when current flows the the resistor \$\endgroup\$ – BHS Oct 11 at 7:35
  • \$\begingroup\$ I understand that spice is designed for IC circuitry, which may not have resistors with excess noise. But if you inspect any Tina Or Ltspice page hosted by a major manufacturer, you will see abundant training on using .noise for a variety of op amp circuitry. \$\endgroup\$ – BHS Oct 12 at 19:48

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