A 25-Gb/s inductorless SiGe BiCMOS receiver for 100-Gb/s optical links

Abstract

This paper presents the design and measurements of a 25-Gb/s inductorless optical receiver in a 0.25-μm SiGe BiCMOS process for 100-Gb/s (25-Gb/s × 4 lines) Ethernet. As the first stage of the proposed optical receiver, a transimpedance amplifier (TIA) employing a pseudo-differential structure with a feedback resistor incorporates DC offset cancellation (DOC) to enhance the input dynamic range. Cascaded by the improved two-stage limiting amplifiers and a 50-Ω output buffer, the receiver achieves high differential swings. For a bit-error rate (BER) of 10−12 at 25 Gb/s, the measured transimpedance gain, bandwidth, sensitivity, and output swing are 63.17 dBΩ, 20.7 GHz, −10.3 dBm, and 352.7 mV, respectively. The power consumption of the entire receiver is 111.6 mW and the core area of the die is 640 μm × 135 μm.