DC-to-15- and DC-to-30-GHz CMOS distributed transimpedance amplifiers

Two broadband transimpedance amplifiers (TIAs) for optical applications were realized in a 0.18-/spl mu/m CMOS technology. The first TIA, cascading two three-stage cascode distributed amplifiers, achieves a transimpedance gain of 58 bB/spl Omega/ and a bandwidth of 15 GHz. The other, using a cascode distributed amplifier, achieves a transimpedance gain of 48 dB/spl Omega/ and a bandwidth of 30 GHz. The TIAs utilize a distributed technique with cascode gain cells to enhance the gain and bandwidth performance. This technique provides TIAs with ultra-broad bandwidth.