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.

Dark-subtracted photocurrent (A)

Required number input.

Incident optical power (W)

Required number input.

Calculate a PIN photodiode's measured electrical responsivity from dark-subtracted photocurrent and incident optical power. 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]

Electrical responsivity (A/W)

The resulting electrical responsivity returned as a number.

• 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.

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  Calculate average backlight supply current from measured electrical power and supply voltage.