A 40-Gb/s Transimpedance Amplifier for Optical Links

This letter presents a low-power transimpedance amplifier (TIA), supporting both 25 and 40-Gb/s communication. It exhibits an optical modulation amplitude sensitivity of -10.6 dBm at 25 Gb/s and -6.4 dBm at 40 Gb/s using a photodiode with a responsivity of 0.55 A/W. The TIA consumes 158 mW from a 2.5 V supply and was manufactured in a 0.13-μm SiGe BiCMOS process. Compared with the state of the art, the presented TIA exhibits a similar sensitivity (at both 25 and 40 Gb/s), while exhibiting a low power consumption for the 40-Gb/s operation.