OPTICAL RECEPTION CIRCUIT

摘要

PURPOSE:To easily compensate the temperature characteristics of an avalanche photodiode and to improve the accuracy of compensation by providing a resistor in parallel to a thermistor and a resistor on a bias voltage generating circuit for compensating the temperature characteristics of the avalanche photodiode. CONSTITUTION:The bias voltage Vr of the avalanche photodiode 1 is controlled by an operational amplifier 2 and a DC/DC converter 3 so that the potential of a point (a) is equal to voltage vref. The potential of the point (a) is determined by the sum of the parallel combined resistance value with the thermistor 4 and the resistor 5 and the resistance value of a resistor 6, and the product of both the resistance values. The voltage Vr is changed by the temperature characteristics of the thermistor 4 to compensate the temperature characteristics of the diode 1. Consequently, the temperature characteristics of the avalanche photodiode 1 can easily be compensated and the accuracy of compensation can be improved.