Use this electronics calculation for a first-pass component, converter, signal, motor, or sensor estimate when the stated operating conditions and units match the device data.

Temperature Kelvin (K)

Required number input.

Bandwidth Hz (Hz)

Required number input.

Resistance Ohms (Ω)

Required number input.

RMS Johnson-Nyquist current noise over an equivalent noise bandwidth; assumes a resistor at thermal equilibrium. The tool evaluates the supplied inputs together and returns the named outputs below; it does not infer omitted operating conditions or change the units shown.^[1]

Noise Amperes (A)

The resulting noise amperes returned as a number.

• SNR, SINAD, THD, SFDR, and integrated-noise results require explicit bandwidth, weighting, reference amplitude, windowing, harmonic set, impedance, and RMS or peak conventions. Values measured under different conditions are not directly comparable.
• Use finite inputs in the displayed units and preserve more precision than the final presentation requires. Independently verify safety-critical, financial, compliance, or production decisions.

Check the result against the current datasheet and worst-case operating corners, then verify the circuit or measurement with simulation and bench testing where failure matters.

• Johnson Noise

  Compute the RMS Johnson-Nyquist noise voltage of a resistor in nanovolts over a measurement bandwidth.

• Accelerometer Noise Density

  Infer white accelerometer noise density from measured RMS noise and equivalent noise bandwidth; colored noise needs spectral analysis.

• Detector Noise Equivalent Power

  Detector noise-equivalent optical power for 1 Hz bandwidth from input-referred current-noise density and responsivity.