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.

Noise Amperes Per Root Hz (A/√Hz)

Required number input.

Responsivity Amperes Per Watt (A/W)

Required number input.

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

Nep Watts Per Root Hz (W/√Hz)

The resulting nep watts per root hz returned as a number.

• Photodetector responsivity, detectivity, quantum efficiency, and noise-equivalent power depend on wavelength, bandwidth, area, bias, temperature, optical coupling, and the stated noise model. Datasheet conditions must match the intended measurement.
• 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.

• Accelerometer Noise Density

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

• Oscillator Phase Noise Simple

  Express single-sideband noise power spectral density relative to carrier power at a specified offset, in dBc/Hz.

• Phototransistor Collector Current

  Approximate phototransistor collector current from incident optical power, photodiode responsivity and transistor current gain.