Patent ID: 6654215
Filing Date: 2003-11-25
Classification: H01L

Abstract:
A photodetector circuit for processing an optical input signal having an input signal magnitude, the photodetector circuit comprising:a power supply having an output terminal; a load device having an input terminal; and an avalanche photodiode coupled between the output terminal and the input terminal, the avalanche photodiode being configured to process the optical input signal; wherein the power supply has a characteristic load line associated with the generation of a bias potential across the avalanche photodiode, the characteristic load line including a substantially horizontal portion for supplying power to the avalanche photodiode with a substantially constant current, the characteristic load line also including a substantially vertical portion for supplying power to the avalanche photodiode with a substantially constant voltage, the power supply being configured to change from a first portion of the characteristic load line to a second portion of the characteristic load line when the bias potential across the avalanche photodiode that is generated by the substantially constant current has a magnitude that is less than a magnitude of the substantially constant voltage.