Automatically adapting forward or reversed biased photodiode detection circuit

摘要

A photodiode detection circuit is used to automatically identify a type of photodiode circuit connected to it (34, 35). The photodiode circuit comprises at least a photodiode. Once the type of photodiode circuit has been identified by applying a current to it (44) and evaluating a voltage occuring at an input of the detection circuit (45) the photodetection circuit adapts itself to it, e.g. a reverse basing voltage is / isn't applied (48) to the photodiode of the photodiode circuit. The result is a photodiode detection circuit which uses a forward or a reversed biased photodiode. The photodiode detection circuit is now in a state to measure light falling on the photodiode. The detection circuit may be part of a light intensity monitoring and controlling circuit which allows to regulate the intensity of a laser beam in an optical disk reading / recording device. <IMAGE>