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.

Quantum efficiency (%)

Photodetector quantum efficiency.

Wavelength (nm)

Wavelength of the incident light.

Compute photodiode responsivity in A/W from quantum efficiency and wavelength. 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]

Responsivity (A/W)

Current produced per watt of optical power.

• Photodiode and phototransistor current depend on wavelength, optical power at the active area, responsivity, bias, gain, temperature, dark current, bandwidth, and load. Shot noise, amplifier noise, saturation, and optical coupling are separate design constraints.
• 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.

• Detector Responsivity Vs Wavelength

  Ideal photodetector responsivity from external quantum efficiency and incident wavelength.

• Detector Quantum Efficiency

  Photon-to-electron quantum efficiency from counted collected electrons and incident photons.

• Phototransistor Collector Current

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