A photodetector receiver circuit for an optical communication system includes an optical photodetector which receives optical signals and converts them into an electrical current. In one illustrative embodiment, a dynamic impedance module which switches the receiver circuit between a high impedance state and a low impedance state and a buffer stage which receives the electrical current and converts the electrical current into a voltage signal compatible with a digital circuit. A method for receiving an optical signal includes, receiving the optical signal and converting it into an electrical pulse train, switching a dynamic impedance module between a high impedance state and a low impedance state, transforming the electrical pulse train into an output voltage signal using a buffer stage, and receiving the output voltage signal by a digital circuit.