Patent ID: 8792785
Filing Date: 2014-07-29
Classification: H04B

Abstract:
1. A circuit for monitoring an optical receiver, wherein said circuit comprises: an avalanche photodiode (APD); a multipath constant flow source configured to convert photocurrent from the APD into first and second currents, the second current having a value different from that of the first current; a first amplifier having a first gain, configured to receive the first current from the APD and provide a first voltage signal; a second amplifier having a second gain different from the first gain, configured to receive the second current from the APD and provide a second voltage signal; a microprocessor configured to (i) supply a bias voltage to the APD and (ii) determine an optical power from the first and second voltage signals; and a digital to analog converter (DAC) that receives an output from the microprocessor and provides a voltage to the multipath constant flow source.