An Energy-Efficient, 60Gbps Variable Transimpedance Optical Receiver in a 90nm SiGe HBT Technology
This paper presents a differential optical receiver integrated circuit (RXIC) with a variable-transimpedance amplifier (VTIA), a two-stage variable-gain amplifier, and 50-Ω output buffer based on a 90-nm SiGe BiCMOS technology. The VTIA incorporates tunable load and feedback resistors to adjust the gain and frequency response and introduces higher dynamic range in the RXIC. Electrical measurements of the RXIC on an FR-4 PCB assembly demonstrate open-eye NRZ data rates up to 60 Gbps, error-free (i.e. 10-11) at 50 Gbps. The total power consumption of the RXIC is 137 mW for an energy efficiency of 2.28 pJ/bit. The transimpedance-bitrate relative to power consumption is among the highest reported relative to the state-of-the-art.