Optical Receiver With Widely Tunable Sensitivity in BiCMOS Technology

A monolithically integrated optical receiver with voltage-controlled sensitivity in 0.6-m BiCMOS technology is presented. The transimpedance variations are achieved by varying the control voltage of the voltage-controlled resistor changing its equivalent resistance. The optical receiver design is based on a P-intrinsic-N photodiode and on a mixed current-mode and voltage-mode approach, by using a current conveyor and a voltage amplifier. Thanks to the current-mode signal processing, the bandwidth of the optical receiver is independent of the photodiode capacitance. A linearity error smaller than 2.92%, a sensitivity dynamic range of 83.2 (38.4 dB), an offset voltage smaller than 0.56 mV, a power consumption less than 4.7 mW, and a bandwidth up to 205.5 MHz are achieved.