Patent ID: 6356375
Filing Date: 2002-03-12
Classification: H03G,H04B

Abstract:
An integrated photodiode and receiver circuit on a substrate, the integrated receiver circuit comprising:a first diffused region in the substrate for receiving an input signal; a first circuit input terminal coupled to the first diffused region; a circuit output terminal; an input amplifier interposed between the first circuit input and receiver output terminals, the input amplifier being configured to receive and amplify the input signal to produce an amplified input signal, and wherein the input amplifier is further configured to vary the gain of the input amplifier responsive to a gain control signal; a bandpass filter interposed between the input amplifier and the circuit output terminal, the bandpass filter being configured to receive and bandpass filter the amplified input signal so as to produce a filtered input signal; a comparator interposed between the bandpass filter and the circuit output terminal, the comparator being configured to compare the filtered input signal to a detection threshold voltage level in order to generate a digital output signal; a delay circuit interposed between the comparator and the circuit output terminal, the delay circuit being configured to receive the digital output signal and generate a delayed digital output signal responsive thereto; an automatic gain control circuit configured to receive the filtered input signal, the automatic gain control circuit comparing the filtered input signal to an automatic gain control threshold voltage and generating the gain control signal responsive thereto; an isolation control signal generator configured to receive the delayed digital output signal and generating an isolation control signal responsive thereto; and an isolation switch interposed between the input amplifier and the automatic gain control circuit, the isolation switch being configured to receive the isolation control signal and, responsive thereto, isolate the automatic gain control circuit from the amplified input signal.