Patent ID: 6876259

Claim:
A circuit for coupling to a photodetector for providing a received signal strength indicator (RSSI) signal comprising: a transimpedance amplifier (TIA) stage coupled to the photodetector for receiving current flowing therethrough and for providing a TIA output signal; a filter circuit having an input port for receiving the TIA output signal and for filtering the TIA output signal to provide a first voltage signal; a dummy TIA stage having a dummy TIA output port for providing a second DC voltage signal; a high gain integrator circuit having a negative input port for receiving the second DC voltage signal, having a positive input port for receiving the first voltage signal and having an output port for providing a high gain integrator output signal therefrom; a transconductance amplifier (TCA) circuit having a negative input port for receiving the second DC voltage signal, having a positive input port for receiving the first voltage signal, and having an output port for providing a first current therefrom; and a second current mirror having an input port for receiving the first current and a second current and for providing the RSSI signal from an output port thereof, the RSSI signal dependent upon the first and second currents.