Patent ID: 6707024
Filing Date: 2004-03-16
Classification: G01J,H01L,H04B

Abstract:
A bias circuit for a photodetector to provide the photodetector that performs electric current amplification according to a supplied bias voltage with the bias voltage, comprising:a power node; and an auto-bias circuit which changes a time constant of the bias circuit for the photodetector according to an optical power received by the photodetector, the auto-bias circuit being connected between the power node and the photodetector; wherein the auto-bias circuit comprises first and a second time constants that are switched according to the optical power received by the photodetector; and wherein the auto-bias circuit has the first time constant when the optical power received by the photodetector decreases rapidly, and has the second time constant that is smaller than the first time constant when the optical power received by the photodetector increases rapidly.