IL300 Linear Optocoupler Vishay IL300 Linear Optocoupler offers a wide 200kHz bandwidth, 130dB Common Mode Rejection (CMR), and high gain stability. The IL300 Optocoupler consists of a high-efficiency AlGaAs LED emitter coupled to two independent PIN photodiodes. The servo photodiode provides a feedback signal which controls the current to the LED emitter. This photodiode provides a photocurrent that is directly proportional to the LED’s incident flux. This servo operation linearizes the LED's output flux and eliminates the LED's time and temperature dependency. The galvanic isolation between the input and the output is provided by a second PIN photodiode located on the output side of the coupler. The output current from this photodiode accurately tracks the photocurrent generated by the servo photodiode.