Patent ID: 9602202
Date: 2017-03-21
CPC Classifications: H04B,H04J

Claim:
1. A method for current replication, the method comprising: receiving, at a photodetector, an optical signal having a plurality of wavelengths and an optical power; responsive to the optical signal received, generating a photodetector current at the photodetector, wherein the photodetector is reverse biased with a bias voltage; outputting the photodetector current from an anode of the photodetector to a first logarithmic amplifier to generate a first output voltage that is linear with the optical power in decibels (dB); generating a copy current using a transimpedance amplifier (TIA) having a first feedback resistor and a second feedback resistor, wherein a negative terminal of the transimpedance amplifier is a cathode of the photodetector, and wherein a TIA output voltage that is linear with the optical power is generated; and outputting the copy current from a positive terminal of the transimpedance amplifier to a second logarithmic amplifier to generate a second voltage that is linear with the optical power in dB.